热区传值问题，大家帮忙看看

我这样写只能获得到一个 $hidden1的值，$hidden的值获取不到，为什么啊

代码如下：

//这是接收传过来的两个值
$hidden1 = $_POST['hidden1'];
$hidden2 = $_POST['hidden2'];

//下面是使用热区传值
<img src="image/vote.jpg" width="640" height="530" border="0" useMap="#Map">
<MAP NAME="Map" id="Map">
<AREA CLASS='fandui' SHAPE='RECT' COORDS='44,490,100,510' href='#' onClick="form1.submit();">
<AREA CLASS='zhichi' SHAPE='RECT' COORDS='168,489,226,509' href='#' onClick="form1.submit();">
<AREA SHAPE='RECT' COORDS='' href='#' onclick=>
</MAP>
<form name="form1" method="post">
<input type="hidden" name="hidden1" value="1">
<input type="hidden" name="hidden2" value="2">
</form>