Notice: Undefined index: message
<p>Notice: Undefined index: message in C:\xampp\htdocs\mywebsite\Untitled9.php on line 27</p>

<pre><code>    &lt;?php  session_start(); 
if ($_GET['message'] == "success" &amp;&amp; $_SESSION['revisit'] == "0") {     
$_SESSION['revisit'] = "1";     ?&gt;     
&lt;script type="text/javascript"&gt;window.alert('Message successfully posted.');&lt;/script&gt;     
&lt;?php } ?&gt;
</code></pre>

<p>Line 27 is....</p>

<pre><code>if ($_GET['message'] == "success" &amp;&amp; $_SESSION['revisit'] == "0") { 
</code></pre>

<p>How do i fix this?</p>
