function login_checkfrm(f)
{	if (f.customer_email.value=="")
	{	alert('Zadejte email  ...');
		f.customer_email.focus();
		return false;
	}
	if (f.customer_password.value=="")
	{	alert('Zadejte heslo  ...');
		f.customer_password.focus();
		return false;
	}
	return true;
}