title: How to populate login textbox UserName (not present in designer file) from a session variable?
body: <p>A question from a beginner without English as mother language.</p>
  <p>I have a Login.aspx file, populated with one <code>asp:HyperLink</code> and one <code>asp:Login</code>. Inside the login control there are labels, textboxes, and validation procedures inside a layout template.</p>
  <p>Inside the designer file, however, there are only hyperlink and login controls. The textbox <code>UserName</code> is absent as all other controls inside the Login control.</p>
  <p>I want to populate UserName with a session variable at page load, i.e. <code>UserName.text=Session(&quot;Fng&quot;).ToString</code> but got error</p>
  <blockquote>
  <p>'UserName' is not declared.</p>
  </blockquote>
  <p>How to work around?</p>