// popup function
function openAWindow( pageToLoad, winName, width, height, center) {
xposition=0; yposition=0;
  if ((parseInt(navigator.appVersion) >= 4 ) && (center)){
      xposition = (screen.width - width) / 2;
      yposition = (screen.height - height) / 2;
   }
  args = "width=" + width + "," 
   + "height=" + height + "," 
   + "location=0," 
    + "menubar=0," 
    + "resizable=1," 
    + "scrollbars=0," 
    + "status=0," 
   + "titlebar=0," 
   + "toolbar=0," 
   + "hotkeys=0," 
    + "screenx=" + xposition + ","  //NN Only 
    + "screeny=" + yposition + ","  //NN Only 
   + "left=" + xposition + ","     //IE Only 
   + "top=" + yposition;           //IE Only 
    window.open( pageToLoad,winName,args ); 
}