function winPopUp(url, width, height) {
  var posLeft = (screen.width - width)/2
  var posTop = (screen.height - height)/2
  var winProperties = 'width='+width+',height='+height+',left='+posLeft+',top='+posTop+',toolbar=yes,resizable=yes,scrollbars=yes'
  win = window.open(url, '', winProperties)
  if (parseInt(navigator.appVersion) >= 4) { win.window.focus() }
}