var win = null;
function NewWindow(mypage, myname, 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';
win = window.open(mypage,myname,settings);

return false;
}