WTF I KEep Getting WEbsite Error Please Help

im using app server and everytime i go to site it says something like failed to connect on config on line 2 or 4 or 12 or something here is my config.php

<?php
//Nolife_x Mpog Spain Config
$link = mssql_connect("GARRETT-D7BCFFC\SQLEXPRESS","sa","Kenman1937");
mssql_select_db("GunzDB");
$opened = 1;
if($opened == 0){
header("Location: Maintenance.php");
}
?>

<?php
//Emblem Upload Config
$DBHost = 'GARRETT-D7BCFFC\SQLEXPRESS';
$DBUser = 'Sa';
$DBPass = 'Kenman1937';
$DB = 'GunzDB';
?>