var win = null;
var w = 600;
var h = 590;
var scroll = 'no';
var myname = 'name';
function popup(mypage) {
 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=no';
 win = window.open(mypage,myname,settings)
}