Ajax validerning form validerar bara när jag har fyllt i

Gör en ajax validerning för kolla om fält är i fyllda och sedan dra ner en röd rad på sidan med information om det är något som missat.

Problemet är att den validerar bara när jag har alla fälten som krävs för att valideras då klagar den och när jag inte har något i fyllt så värka inget hända :/

Någon som kan se vad jag har för fel i scriptet.

<?php
session_start();
include("../../mysql.php");
include("../../languages/languages.php");

if(!(int)$_POST['advertisers_users_company_name'])
{
	die(msg(0,"Invalid company name - Company Name is required."));
}

if(!(int)$_POST['advertisers_users_street_address1'])
{
	die(msg(0,"Faulty street address - Enter a valid street address."));
}

if(!(int)$_POST['advertisers_users_city'])
{
	die(msg(0,"Invalid City - Please enter a valid city or town."));
}

if(!(int)$_POST['advertisers_users_account_name'])
{
	die(msg(0,"The campaign's short name is missing."));
}

     $act = mysql_real_escape_string($_GET['act']);
     $advertisers_users_username = mysql_real_escape_string($_POST['advertisers_users_username']);
     $advertisers_users_password = mysql_real_escape_string($_POST['advertisers_users_password']);
     $advertisers_users_account_name = mysql_real_escape_string($_POST['advertisers_users_account_name']);
     $advertisers_users_currency = mysql_real_escape_string($_POST['advertisers_users_currency']);
     $advertisers_users_timezone = mysql_real_escape_string($_POST['advertisers_users_timezone']);
     $advertisers_users_industry = mysql_real_escape_string($_POST['advertisers_users_industry']);
     $advertisers_users_buy_smsnetwork_ads = mysql_real_escape_string($_POST['advertisers_users_buy_smsnetwork_ads']);
     $advertisers_users_company_name = mysql_real_escape_string($_POST['advertisers_users_company_name']);
     $advertisers_users_street_address1 = mysql_real_escape_string($_POST['advertisers_users_street_address1']);
     $advertisers_users_street_address2 = mysql_real_escape_string($_POST['advertisers_users_street_address2']);
     $advertisers_users_city = mysql_real_escape_string($_POST['advertisers_users_city']);
     $advertisers_users_state = mysql_real_escape_string($_POST['advertisers_users_state']);
     $advertisers_users_zip_code = mysql_real_escape_string($_POST['advertisers_users_zip_code']);
     $advertisers_users_country = mysql_real_escape_string($_POST['advertisers_users_country']);
     $advertisers_users_eu_vat_country = mysql_real_escape_string($_POST['advertisers_users_eu_vat_country']);
     $advertisers_users_eu_vat_number = mysql_real_escape_string($_POST['advertisers_users_eu_vat_number']);
     $advertisers_users_agency = mysql_real_escape_string($_POST['advertisers_users_agency']);

     $sql1 = "UPDATE Advertisers_users SET
     advertisers_users_username = '$advertisers_users_username',
     advertisers_users_password = '$advertisers_users_password',
     advertisers_users_account_name = '$advertisers_users_account_name',
     advertisers_users_currency = '$advertisers_users_currency',
     advertisers_users_timezone = '$advertisers_users_timezone',
     advertisers_users_industry = '$advertisers_users_industry',
     advertisers_users_buy_smsnetwork_ads = '$advertisers_users_buy_smsnetwork_ads',
     advertisers_users_company_name = '$advertisers_users_company_name',
     advertisers_users_street_address1 = '$advertisers_users_street_address1',
     advertisers_users_street_address2 = '$advertisers_users_street_address2',
     advertisers_users_city = '$advertisers_users_city',
     advertisers_users_state = '$advertisers_users_state',
     advertisers_users_zip_code = '$advertisers_users_zip_code',
     advertisers_users_country = '$advertisers_users_country',
     advertisers_users_eu_vat_country = '$advertisers_users_eu_vat_country',
     advertisers_users_eu_vat_number = '$advertisers_users_eu_vat_number',
     advertisers_users_agency = '$advertisers_users_agency'
     WHERE advertisers_users_id = '$act' AND advertisers_access_id = '{$_SESSION['sess_id']}'";
     mysql_query($sql1, $conn) or die(mysql_error());

//echo msg(1,"registered.html");

function msg($status,$txt)
{
	return '{"status":'.$status.',"txt":"'.$txt.'"}';
}
?>