var popup = null;

function newWindow(Page, windowname)
  {
    var h = 500;
    var w = 550;
    var winl = (screen.width - w) / 2;
    var wint = (screen.height - h) / 2;
    winDims = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars=yes';
    popup=window.open(Page,windowname, winDims);
  }