var emailfilter=/^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i

function checkmail(e)
{
	var returnval=emailfilter.test(e.value)
	if (returnval==false){
		alert("Please enter a valid email address.")
	e.select()
}
	return returnval
}