function fnShowMessageWindow(message, width, height) {

  var objMessageWindow = document.createElement('DIV');
  objMessageWindow.id='MessageWindow';
  document.getElementsByTagName ('body')[0].appendChild(objMessageWindow);

  var leftPos = (document.body.clientWidth-width)/2, topPos = (document.body.clientHeight-height)/2;

  objMessageWindow.style.left=leftPos;
  objMessageWindow.style.top=document.body.scrollTop+topPos;
  objMessageWindow.style.width=width;
  objMessageWindow.style.height=height;
  objMessageWindow.innerHTML='<table align="center" height="100%"><tr><td height="100%">'+message+'</td></tr></table>';
  objMessageWindow.style.visibility="visible";

  return true;
}