function validate_email(field,alerttxt)
{
with (field)
	{
	apos=value.indexOf("@");
	dotpos=value.lastIndexOf(".");
	if (apos<1||dotpos-apos<2) 
	 {alert(alerttxt);return false;}
	else {return true;}
	}
}

function validate_form(thisform)
{
	with (thisform)
	{

if (validate_email(email,"No es valida la dirección de Correo!")==false)
  {email.focus();return false;}
	}
}