function documentKeyDownHandler(e)
{
	var keyCode = 0;
	var tagName = "";

	if(document.all) // IE
	{
		keyCode = event.keyCode;
		tagName = event.srcElement.tagName;
	}
	else if(document.getElementById) // every other modern browser
	{
		keyCode = e.which;
		tagName = e.target.tagName;
	}

	// prevent unintentional form submission by cancelling enter unless we are in a <textarea>
	if((keyCode !== null) && (keyCode === 13))
	{
		if(tagName.toLowerCase() != "textarea")
		{
			event.returnValue = false;
			event.cancel = true;
		}
	}
}

// handle key downs
document.onkeydown = documentKeyDownHandler;

function doPostBackOnEnter(eventTarget, eventArgument, event)
{
	var doPostBack = false;

	if(document.all) // IE
	{
		if(event.keyCode === 13)
		{
		    doPostBack = true;
		}
	}
	else if(document.getElementById) // every other modern browser
	{
		if(event.which === 13) 
		{
		    doPostBack = true;
		}
	}

	if(doPostBack) 
	{
	    __doPostBack(eventTarget, eventArgument);
	}
}