کار نکردن دستور z-index برای دو div

[PersianSkyTeam]

اینو تست کنید :

#box1
{
   color: #000000;
   font-family: Arial;
   font-size: 13px;
   -moz-box-shadow: 0px 0px 13px #000000;
   -webkit-box-shadow: 0px 0px 13px #000000;
   box-shadow: 0px 0px 13px #000000;
}
#box2
{
   color: #000000;
   font-family: Arial;
   font-size: 13px;
}

کد :

<input type="submit" id="box1" name="" value="box1" style="position:absolute;left:109px;top:179px;width:213px;height:51px;z-index:1;">
<input type="submit" id="box2" name="" value="box2" style="position:absolute;left:109px;top:230px;width:213px;height:51px;z-index:2;">