Is there anyway I can use javascript to block popup from another website (iframe)?

Example: I have a website, which iframe to several other sites. One of them has a popup script like this:

<script type=text/javascript>

var popunder=new Array()

popunder[0]=http://www.target.com



//Specify the width and height of new popunder window (in pixels).

var width = '700'; 

var height = '450';



//these are obvious variables. set yes or no.

var p = 'scrollbars=yes, resizable=yes, toolbar=yes,' + 'menubar=yes, status=yes, location=yes, left=85, top=20, height=' + height + ',width=' + width;



// Load new PopUnder only once per browser session? (0=no, 1=yes)

// Putting 0 will cause the Popunder to load every time page is loaded

// Specifying 1 will cause it to load only once per session

var one_time=0



// That's it! Don't edit the code below unless you're really good. :-P //



function get_cookie(Name) {

  var search = Name + =

  var returnvalue = ;

  if (document.cookie.length > 0) {

    offset = document.cookie.indexOf(search)

    if (offset != -1) { // if the cookie exists

      offset += search.length

      //set the index of beginning value

      end = document.cookie.indexOf(;, offset);



    if (end == -1) // set the index of the end of cookie value

         end = document.cookie.length;

         returnvalue = unescape(document.cookie.substring(offset, end))

      }

   }

  return returnvalue;

}



function loadornot(){

if (get_cookie('popunder')==''){

load_pop_power()

document.cookie=popunder=yes

}

}



function load_pop_power(){

win2 = window.open(popunder[Math.floor(Math.random()*(popunder.length))], bw, p)

win2.blur()

window.focus()

}



if (one_time==0)

load_pop_power()

else

loadornot()

</script>

Provide that this popup cannot be block and user have a low security setting on firefox or IE.

I have the ff. iframe on the site: (iframe.php)

<iframe src=http://friend.com/pop.php></iframe>

What should i do on the iframe.php page to prevent popup?