function validar_login(form) {

	if (form.email.value.indexOf('@') < 0 || form.email.value.indexOf('.') < 0 || form.email.value.indexOf(',') > 0) { alert('Mail adress not correct'); form.email.focus(); return false; }
	if (form.clave.value == '') { alert('Please enter your password.'); form.clave.focus(); return false; }

	return true;

}