// JavaScript Document
function isEmailAddress(theElement, nombre_del_elemento )
{
var s = theElement.value;
var filter=/^[A-Za-z][A-Za-z0-9_]*@[A-Za-z0-9_]+\.[A-Za-z0-9_.]+[A-za-z]$/;
if (s.length == 0 ) return false;
if (filter.test(s)) return true;
else
alert("The email entered is not correct.");
theElement.focus(); return false;
}