function pulsarTecla(e) 
{
	ie4 = (document.all) ? true:false
	if (!ie4) 
	{
		if ( e.which == 13 ) submitForm('login');
	}
	if (ie4) 
	{
		if ( event.keyCode == 13) submitForm('login');
	}	   
}
function tieneFoco()
{
	var ns4 = (document.layers && !dom) ? true : false;
	document.onkeydown = pulsarTecla;
	if (ns4) document.captureEvents(Event.KEYPRESS)
}
function submitForm(elementId) 
{
	var myForm = document.getElementById(elementId);
	myForm.submit();
}