$_SERVER['HTTP_ORIGIN'] doesn't work
<p>When I use <code>$_SERVER['HTTP_ORIGIN']</code>.</p>

<pre class="lang-html prettyprint-override"><code>echo $_SERVER['HTTP_ORIGIN'] ;
</code></pre>



<p>Return
Notice: Undefined index: HTTP_ORIGIN in D:\xampp\htdocs\safe\test.php on line 12</p>

<p>What is Wrong?!</p>