how to check internetexplorer popup block is enabled or not?

In my webpage how to check internet explorer popup block is enabled or not using javascript?Please don't post url.
Please reply asap.
i'm using this code please check and modify once.

<script language="javascript">     var popup;     testwindow=window.open("","testwindow");     if(testwindow)     {     popup=false;     alert("PopUp Block is closed");     testwindow.close();     }     else     {     popup=true;     alert("Popup Block is open");     testwindow.close();     }script>

 
Thanks & Regards
Hari