var win = null;

function newWindow(mypage,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=no, location=no, menubar=no, toolbar=no, status=no';
  win = window.open(mypage, '', settings);
}