Script Manager Popup JavaScript

function popup(url, w, h)
{
var width = w;
var height = h;
var left = (screen.width - width) / 2;
var top = (screen.height - height) / 2;
var params = 'width=' + width + ', height=' + height; params += ', top=' + top + ', left=' + left;
params += ', directories=no'; params += ', location=no'; params += ', menubar=no'; params += ', resizable=yes'; params += ', scrollbars=yes'; params += ', status=no';
params += ', toolbar=no'; newwin = window.open(url, 'windowname5', params);
if (window.focus) {
newwin.focus()
} return false;
}