function OpenWindow( sUri, iWidth, iHeight )
{
  var sWindowName = 'win' + Math.floor( Math.random()*1000 )
  return OpenWindow0(sWindowName,sUri,iWidth,iHeight)
}

function OpenWindow0( sWindowName, sUri, iWidth, iHeight )
{
  var iRealWidth = iWidth ? iWidth : 600
  var iRealHeight = iHeight ? iHeight : screen.height - 300
  var iLeft = Math.round( (screen.width-iRealWidth)/2 )
  var iTop =  Math.round( (screen.height-iRealHeight)/2 ) - 35
  var sWindowOptions = 'status=yes,menubar=no,toolbar=no'
  sWindowOptions += ',resizable=yes,scrollbars=yes,location=no'
  sWindowOptions += ',width='  + iRealWidth
  sWindowOptions += ',height=' + iRealHeight
  sWindowOptions += ',left='   + iLeft
  sWindowOptions += ',top='    + iTop
  var oWindow = window.open( sUri, sWindowName, sWindowOptions )
  oWindow.focus()
  return oWindow
}