No _GET

inventory.php

<?php
//So when you login you're redirected to http://.../inventory?context=index which is this page
session_start();

if($_SESSION['LOGIN_STATUS'] != "OK"){
    session_unset();
    session_destroy();
    echo 'You are not logged in, redirecting in 2 seconds
              <meta http-equiv="Refresh" content="2; URL=index.php">';
}else{
include('./header.php');

//I wrote the following two lines to get the code to work, but I feel like I must be missing something.
//Before I defined the below, this page was just blank.
//$context = $_GET['context']?$_GET['context']:'';
//$doqtype = $_GET['doqtype']?$_GET['doqtype']:'';

//sam inventory
if($context == "index"){
//   Do Stuff
}