Undefined index in PHP
<p>Good day!</p>

<p>I am having the following error in my code:</p>

<pre><code>&lt;?php
if (!$_POST['SUBMIT']){   //ERROR: Undefined index
?&gt;
    &lt;H2&gt;Add Employee&lt;/H2&gt;
    &lt;form action="&lt;?php print $_SERVER['PHP_SELF']; ?&gt;" method="POST"&gt;
    &lt;table width="400" border="0" cellspacing="1" cellpadding="2"&gt;
       &lt;tr&gt;
            &lt;td width="100"&gt;SSN&lt;/td&gt;
            &lt;td&gt;&lt;input name="SSN" type="text" id="SSN"&gt;&lt;/td&gt;
       &lt;/tr&gt;
       &lt;tr&gt;
            &lt;td width="100"&gt;&amp;nbsp;&lt;/td&gt;
            &lt;td&gt;&lt;input name="SUBMIT" type="SUBMIT" id="ADD" value="ADD"&gt;&lt;/td&gt;
       &lt;/tr&gt;
    &lt;/table&gt;
    &lt;/form&gt;
 &lt;?php
    }
    else {
    //code here
    }
?&gt;
</code></pre>

<p>How can I remove the error above? Thank you.</p>
