function btnSubmitEmail_OnClick()
   {
      var txtName = window.document.getElementById( "txtName" );
      var txtEmail = window.document.getElementById( "txtEmail" );
      var ddlOccupation = window.document.getElementById( "ddlOccupation" );
      
      if( txtName.value.length < 1 )
      {
         alert( 'Name is required' );
         txtName.focus();
         return;
      }
      
      if( txtEmail.value.length < 1 )
      {
         alert( 'Email is required' );
         txtEmail.focus();
         return;
      }
      
      var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i

      if ( !filter.test( txtEmail.value ) )
      {
         alert( 'Please check the email address' );
         txtEmail.focus();
         return false;
      }
      
      if( ddlOccupation.selectedIndex < 1 )
      {
         alert( 'Occupation is required' );
         ddlOccupation.focus();
         return;
      }
   
      var theIFrame = window.document.getElementById( "theIFrame" );
         
      theIFrame.src = iFrameUrl + '?name=' + escape( txtName.value ) + '&email=' + txtEmail.value + '&occupation=' + ddlOccupation.options[ ddlOccupation.selectedIndex ].value;
      
      var eEmailSignUpForm = window.document.getElementById( "EmailSignUpForm" );
      var eEmailSignUpThankYou = window.document.getElementById( "EmailSignUpThankYou" );
      
      eEmailSignUpForm.style.display = 'none';
      eEmailSignUpThankYou.style.display = 'block';
   }