Pop up Kodunu Ortalayabilecek?

<script type="text/javascript">


var popurls=new Array()
popurls[0]="http://site1.com"
popurls[1]="http://site2.com"
popurls[2]="http://site3.com"


function openpopup(popurl){
var winpops=window.open(popurl,"","width=900,height=600,scrollbars,resizable")
}

openpopup(popurls[Math.floor(Math.random()*(popurls.length))])

</script>