var win = null;
function popup(mypage,w,h){
 LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
 TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
 h = h + 20;
 w = w + 20;
 settings =
 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+'no'+',status='+'no'+',resizable'
 winName = 'winName'+w+h;
 window.open(mypage,winName,settings);
}