Possible Duplicate:
PHP: “Notice: Undefined variable” and “Notice: Undefined index”

Good day!

I am having the following error in my code:

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

How can I remove the error above? Thank you.