//popup window
function popupw(url,name,h,w)
{
  var l=(screen.width-w)/2
  var t=(screen.height-h)/2
  var
w=window.open(url,name,"scrollbars=1,resizable=1,left="+l+",top="+t+",width="+w+",height="+h)
  if(navigator.platform.indexOf("Mac")!=-1) {
    w.moveTo(l,t)
  }
  return w
}