You could try this in the code behind or your usercontrol:

dynamic node = new umbraco.MacroEngines.DynamicNode(umbraco.NodeFactory.Node.GetCurrent());
siteName.Text = node._siteName; 

Jeroen

Thanks Jeroen, how do I add this to my .ascx file?

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="emintRegister.ascx.cs" Inherits="umbraco.emintControls.usercontrols.BrandHub.emintRegister" %>
<div id="message" runat="server"> </div>
<div class="registration_container" id="regFrom" runat="server">
  <div style="color: Red">
    <asp:Literal ID="additionalErrors" runat="server"></asp:Literal>
  </div>
  <asp:ValidationSummary ID="ValidationSummary" runat="server" ValidationGroup="Registration" HeaderText="You received the following errors:" ShowSummary="False"></asp:ValidationSummary>
  <div class="employee">
  <h3>Are you an employee of <asp:Label ID="companyName1" runat="server" Text="companyName"></asp:Label>?</h3>
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td class="col1"><p><strong>Are you an employee of <asp:Label ID="companyName2" runat="server" Text="companyName"></asp:Label>?</strong></p></td>
      <td class="col2"><asp:RadioButtonList ID="isAnEmployee" runat="server" RepeatLayout="Flow" RepeatColumns="2" CssClass="isEmployee">
          <asp:ListItem Text="Yes" Value="1"></asp:ListItem>
          <asp:ListItem Text="No" Value="2"></asp:ListItem>
        </asp:RadioButtonList></td>
      <td class="col3">&nbsp;</td>
    </tr>
  </table>
  </div>
  <div class="aboutyou">
  <h3>About you</h3>
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td class="col1"><p><strong>First name</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="givenNames" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="givenNamesRequired" runat="server" ErrorMessage="Please enter first name" ControlToValidate="givenNames" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="givenNameValid" runat="server" ErrorMessage="First name is not valid" ControlToValidate="givenNames" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr>
      <td class="col1"><p><strong>Last name</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="familyName" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="familyNameRequired" runat="server" ErrorMessage="Please enter last name" ControlToValidate="familyName" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="familyNameValid" runat="server" ErrorMessage="Family name is not valid" ControlToValidate="familyName" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
  </table>
  </div>
  <div class="yourdetails">
  <h3>Your details</h3>
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr id="emailMessage1">
      <td colspan="3"><p class="details"> All full-time and temporary Brand contractors, with an [[email protected]] email address must register as an employee.</p></td>
    </tr>
    <tr id="emailMessageSubBrand">
      <td colspan="3"><p class="details"> If your email ends with [[email protected]], please check this box:
          <input name="subbrand" id="subbrand" type="checkbox" runat="server" class="subbrand" />
        </p></td>
    </tr>
    <tr id="emailTr">
      <td class="col1"><p><strong>Email address prefix</strong> (required)</p></td>
      <td class="col2"><div class="employeeEmail">
          <div class="employeeEmailAddress">
            <asp:TextBox class="long_input employeeEmail" ID="employeeEmail" runat="server" MaxLength="250"></asp:TextBox>
          </div>
          <div class="emailSuffix">
            <p class="details" style="color: #999;" id="currentEmployeeEmail">@brand.com</p>
          </div>
        </div></td>
      <td class="col3"><asp:RequiredFieldValidator ID="employeeEmailRequired" runat="server" ErrorMessage="Please enter your email address" ControlToValidate="employeeEmail" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="employeeEmailValid" runat="server" ErrorMessage="Email is not valid" ControlToValidate="employeeEmail" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator>
        <p class="details"> This is also your username</p></td>
    </tr>
    <tr id="employeeEmailMessage2">
      <td colspan="3"><p class="details"> Please do not copy and paste your email address prefix into the <b>Retype email address prefix</b> field. <br>
      Incorrectly typed email addresses cannot be verified and will not be given access.</p></td>
    </tr>
    <tr id="employeeEmailRetype">
      <td class="col1"><p><strong>Retype email address prefix</strong> (required)</p></td>
      <td class="col2"><div class="employeeEmail">
          <div class="employeeEmailAddress">
            <asp:TextBox class="long_input employeeEmailConfirm" ID="employeeEmailConfirm" runat="server" MaxLength="250"></asp:TextBox>
          </div>
          <div class="emailSuffix">
            <p class="details" style="color: #999;" id="currentEmployeeEmailConfirm"> @brand.com</p>
          </div>
        </div></td>
      <td class="col3"><asp:CompareValidator ID="employeeEmailMismatch" runat="server" ErrorMessage="Your email address must match" ControlToCompare="employeeEmail" ControlToValidate="employeeEmailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:CompareValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="employeeEmailConfirmValid" runat="server" ErrorMessage="Email is not valid" ControlToValidate="employeeEmailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator>
        <asp:RequiredFieldValidator ID="requiredemployeeEmail" runat="server" ErrorMessage="Please enter your email address" ControlToValidate="employeeEmailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator></td>
    </tr>
    <tr id="nonemployeeEmail">
      <td class="col1"><p><strong>Email address</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input email" ID="email" runat="server" MaxLength="250"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="emailRequired" runat="server" ErrorMessage="Please enter your email address" ControlToValidate="email" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?$" ID="emailValid" runat="server" ErrorMessage="Email is not valid" ControlToValidate="email" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator>
        <p class="details"> This is also your username</p></td>
    </tr>
    <tr id="nonemployeeEmailMessage">
      <td colspan="3"><p class="details"> Please do not copy and paste your email address into the <b>Retype email address</b> field. <br>
          Incorrectly typed email addresses cannot be verified and will not be given access.</p></td>
    </tr>
    <tr id="nonemployeeEmailRetype">
      <td class="col1"><p><strong>Retype email address</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input emailConfirm" ID="emailConfirm" runat="server" MaxLength="250"></asp:TextBox></td>
      <td class="col3"><asp:CompareValidator ID="emailMismatch" runat="server" ErrorMessage="Your email address must match" ControlToCompare="email" ControlToValidate="emailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:CompareValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?$" ID="emailConfirmValid" runat="server" ErrorMessage="Email is not valid" ControlToValidate="emailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator>
        <asp:RequiredFieldValidator ID="requiredEmail" runat="server" ErrorMessage="Please enter your email address" ControlToValidate="emailConfirm" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator></td>
    </tr>
    <tr id="companyRow">
      <td class="col1"><p><strong>Company name</strong> (required)</p></td>
      <td class="col2"><asp:TextBox ID="company" runat="server" MaxLength="30" CssClass="long_input prefillFake companyName" Text="Please enter company name"></asp:TextBox></td>
      <td class="col3"><asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z0-9 '_&,().-]{0,30}$" ID="companyValid" runat="server" ErrorMessage="Company is not valid" ControlToValidate="company" Display="Dynamic" ValidationGroup="Registration"></asp:RegularExpressionValidator>
        <asp:CompareValidator ID="companyValidator" runat="server" ErrorMessage="Please enter company name." ControlToValidate="company" Display="Dynamic" ValidationGroup="Registration" ValueToCompare="Please enter company name" Operator="NotEqual"></asp:CompareValidator>
        <p class="details"> Please enter company name</p></td>
    </tr>
    <tr>
      <td class="col1"><p><strong>Job title</strong></p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="title" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RegularExpressionValidator ValidationExpression="^[\w\s]{1,30}$" ID="titleValid" runat="server" ErrorMessage="Job Title is not valid" ControlToValidate="title" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr id="departmentRow">
      <td class="col1"><p><strong>Department</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="department" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="departmentRequired" runat="server" ErrorMessage="Please enter department" ControlToValidate="department" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[\w\s &()+-]{1,30}$" ID="departmentValid" runat="server" ErrorMessage="Department is not valid" ControlToValidate="department" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr>
      <td class="col1"><p><strong>Contact phone number</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="contactPhoneNumber" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="contactPhoneNumberRequired" runat="server" ErrorMessage="Please enter contact phone number" ControlToValidate="contactPhoneNumber" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[\w\s &()+-]{1,30}$" ID="contactNumberValid" runat="server" ErrorMessage="Contact phone number is not valid" ControlToValidate="contactPhoneNumber" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr>
      <td class="col1"><p><strong>Alternative phone number</strong></p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="alternativePhoneNumber" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RegularExpressionValidator ValidationExpression="^[\w\s &()+-]{1,30}$" ID="alternativeNumberValid" runat="server" ErrorMessage="Alternative phone number is not valid" ControlToValidate="alternativePhoneNumber" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
  </table>
  </div>
  <div class="referrer">
    <h3>Please enter the details of the Brand contact who referred you to this site</h3>
  <table width="100%" border="0" cellspacing="0" cellpadding="0" id="referRows">
    <tr id="reRefer1">
      <td class="col1"><p><strong>Contact&#8217;s name</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="referContactName" runat="server" MaxLength="250"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="referContactNameRequired" runat="server" ErrorMessage="Please enter your contact&#8217;s name" ControlToValidate="referContactName" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="referContactNameValid" runat="server" ErrorMessage="Contact name is not valid" ControlToValidate="referContactName" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr id="reRefer2">
      <td class="col1"><p><strong>Contact&#8217;s division</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="referContactDivision" runat="server" MaxLength="250"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="referContactDivisionRequired" runat="server" ErrorMessage="Please enter your contact&#8217;s division" ControlToValidate="referContactDivision" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z '_&,().-]{1,30}$" ID="referContactDivisionValid" runat="server" ErrorMessage="Contact division is not valid" ControlToValidate="referContactDivision" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr id="reRefer3">
      <td class="col1"><p><strong>Contact&#8217;s email address</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="referContactEmail" runat="server" MaxLength="250"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="referContactEmailRequired" runat="server" ErrorMessage="Please enter your contact&#8217;s email address" ControlToValidate="referContactEmail" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?$" ID="referContactEmailValid" runat="server" ErrorMessage="Contact email is not valid" ControlToValidate="referContactEmail" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
    <tr id="reRefer4">
      <td class="col1"><p><strong>Contact&#8217;s phone number</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="referContactPhoneNumber" runat="server" MaxLength="30"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="referContactPhoneNumberRequired" runat="server" ErrorMessage="Please enter your contact&#8217;s phone number" ControlToValidate="referContactPhoneNumber" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ValidationExpression="^[\w\s &()+-]{1,30}$" ID="referContactNumberValid" runat="server" ErrorMessage="Contact phone number is not valid" ControlToValidate="referContactPhoneNumber" ValidationGroup="Registration" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
  </table>
  </div>
  <div class="security">
    <h3>Account security</h3>
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr id="passwordRow1">
      <td class="col1"><p><strong>Password</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="password" runat="server" TextMode="Password"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="passwordRequired" runat="server" ErrorMessage="Please enter password" ControlToValidate="password" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:RegularExpressionValidator ID="valPassword" runat="server" ControlToValidate="password" ErrorMessage="Minimum password length is 6 characters" ValidationExpression=".{6}.*" Display="Dynamic"></asp:RegularExpressionValidator>
        <p class="details"> Must be at least 6 alphanumeric characters</p></td>
    </tr>
    <tr id="passwordRow2">
      <td class="col1"><p><strong>Retype password</strong> (required)</p></td>
      <td class="col2"><asp:TextBox class="long_input" ID="confirmPassword" runat="server" TextMode="Password"></asp:TextBox></td>
      <td class="col3"><asp:RequiredFieldValidator ID="confirmPasswordRequired" runat="server" ErrorMessage="Please enter password" ControlToValidate="confirmPassword" ValidationGroup="Registration" Display="Dynamic"></asp:RequiredFieldValidator>
        <asp:CompareValidator ID="confirmPasswordValidator" runat="server" ErrorMessage="Your password must match" ControlToCompare="password" ControlToValidate="confirmPassword" ValidationGroup="Registration" Display="Dynamic"></asp:CompareValidator>
        <asp:RegularExpressionValidator ID="confirmvalPassword" runat="server" ControlToValidate="confirmPassword" ErrorMessage="Minimum password length is 6 characters" ValidationExpression=".{6}.*" Display="Dynamic"></asp:RegularExpressionValidator></td>
    </tr>
  </table>
  </div>
  <div class="signup">
  <p class="fine_print">
    <asp:CheckBox ID="termsAndConditions" runat="server"></asp:CheckBox>
    I have read and agreed to the <a runat="server" id="termsLink" href="#" target="_blank"> Terms and Conditions</a> and <a runat="server" id="privacyLink" href="#" target="_blank"> Privacy Statement</a>. <span style="font-size: 10px; margin-left: 5px;">
    <asp:CustomValidator ID="termsRequireed" runat="server" ValidationGroup="Registration" ErrorMessage="You must agree to terms and conditions" OnServerValidate="termsRequireed_ServerValidate" ClientValidationFunction="TermsRequired"></asp:CustomValidator>
    </span></p>
    <p class="fine_print">
    <input name="newsletter" id="newsletter" type="checkbox" value="Checked" checked disabled />
    By registering, you agree to receive <strong>Brand Brand Central Updates</strong>, an email notification containing important changes relating to Brand&rsquo;s Brand Standards, templates or other materials.</p>
    <asp:Button ID="ButtonSignup" runat="server" Text="Register" OnClick="ButtonSignup_Click" ValidationGroup="Registration" Display="Dynamic" CssClass="button"></asp:Button>
    </div>
  </div>

Your UserControl has a code behind (emintRegister.ascx.cs). You can use this example there: 

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        dynamic node = new umbraco.MacroEngines.DynamicNode(umbraco.NodeFactory.Node.GetCurrent());
        siteName.Text = node._siteName;
    }
}

 Jeroen

is working on a reply...