My control names get changed at runtime

[VBRookie]

This is a problem because how can I reference the control in the code behind file if it has changed at runtime. Example:


In the aspx file I have the following control:

<input type=&quot;hidden&quot; id=&quot;EnterHit&quot; value=&quot;N&quot; runat=&quot;server&quot; />

In my code-behind file I have the following code:

protected System.Web.UI.HtmlControls.HtmlInputHidden EnterHit;

private void Page_Load(object sender, System.EventArgs e)
		{
           if (EnterHit.Value == "Y")
			{
				... some code here
			}
         }

I also have a javascript routine that changes the value of the hidden variable if the enter key is pressed. It is:

<script language=javascript>
function FindKey(){
if (event.keyCode == 13) {document.frmMain.EnterHit.value='Y';}
}
</script>

I get an error that says:

Microsoft JScript runtime error: 'document.frmMain.EnterHit' is null or not an object


Can someone please point me in the right direction?

- VBRookie