在$ _POST中获取imagemap的值

Question

点击头部后，我没有收到任何返回值，我该怎么办？

form method="post" id="form">
<img name="wew" src="wew.jpg" name="body"  width="257" height="376" id="wew" usemap="#m_wew" alt="" /><map name="m_wew" id="m_wew">

<area shape="poly" coords="132,9,127,11,122,13,118,16,118,18,117,21,117,24,117,28,116,31,114,31,114,35,114,38,115,42,117,44,117,45,122,48,124,48,128,49,131,49,137,49,141,48,144,46,146,44,148,42,149,41,150,35,150,33,148,30,148,27,148,22,147,18,146,15,142,11,138,10,135,10,133,9" href="javascript:document.getElementById('form').submit();;"  Value="Head" title="Head" name="Head" alt="Head" />
<?php

if(isset($_POST['Head'])){

$_SESSION['Head']=$_POST['Head'];
                  $sub=$_SESSION['Head'];


}
?>