function EMail(s) {
  var a = false;
  var res = false;
	if(typeof(RegExp) == 'function')
	{
	var b = new RegExp('abc');
	if(b.test('abc') == true){a = true;}
	}
	
	if(a == true)
	{
	reg = new RegExp('^([a-zA-Z0-9\\-\\.\\_]+)'+'(\\@)([a-zA-Z0-9\\-\\.]+)'+'(\\.)([a-zA-Z]{2,4})$');
	res = (reg.test(s));
	}
	else
    {
    res = (s.search('@') >= 1 &&
           s.lastIndexOf('.') > s.search('@') &&
           s.lastIndexOf('.') >= s.length-5)
	}
  	return(res);
}