document.onkeydown = CancelEnter

function CancelEnter(e)
{
	var intKeyCode = 0 ;
	var strTagName = "" ;
	var blnSubmitForm = false ;

	if(document.all)
	{
		intKeyCode = event.keyCode ;
		strTagName = event.srcElement.tagName ;
	}
	else
	{
		intKeyCode = e.which ;
		strTagName = e.target.tagName ;
	}
	if((intKeyCode != null && intKeyCode == 13))
	{
		if(strTagName.toLowerCase()!= "textarea")
		{

			blnSubmitForm = true ;
		}
	}
	if(blnSubmitForm == true)
	{
		__doPostBack('LoginCtl1$btnLogin','');
	}
}