Popup form on Screen Center Javascript

Popup Form on Center 

to popup the form on Screen Center use the below Script

Example :

<script language="javascript">
var popupWindow = null;
function centeredPopup(url,winName,w,h,scroll){
LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
settings =
'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable'
popupWindow = window.open(url,winName,settings)
}
</script>
<p><a href="http://www.quackit.com/common/link_builder.cfm" onclick="centeredPopup(this.href,'myWindow','500','300','yes');return false">Centered Popup</a></p>