i am using chained select box in http://www.dynamicdrive.com/dynamici...ects/index.htm

i wanna send all three selectbox value to x2.php. But i can send just last one why ?

(my full codes is in attachment. )

sample.html
HTML Code:
<html>

<head>
<title>Chained Selects</title>
<script language="javascript" src="chainedmenu.js"></script>
<script language="javascript" src="config.js"></script>
</head>
<body onLoad="initListGroup('chainedmenu', document.listmenu0.firstlevel, document.listmenu0.secondlevel, document.listmenu0.thirdlevel, 'savestate')">

<form name="listmenu0" action="x2.php" method="POST">
<table align="center">
	<tr>
		<td><select name="firstlevel"></select></td>
		<td><select name="secondlevel"></select></td>
		<td><select name="thirdlevel"></select></td>
		<td>
			<input type="button" value="Go" onClick="goListGroup(document.listmenu0.firstlevel, document.listmenu0.secondlevel, document.listmenu0.thirdlevel)">
			<input type="button" value="Reset" onClick="resetListGroup('chainedmenu')">
			<input name="" type="submit" value="Submit">
		</td>
	</tr>
</table>
</form>
</body>

</html>
x2.php

PHP Code:
<?php
foreach($_POST as $a=>$b){
    echo 
$a." -  ".$b."<br/>";
}

?>