function showImages(oid, id, w, h) {

   if (w < 320) w = 320;
   if (h < 256) h = 256;

   var screenw = screen.availWidth;
   var screenh = screen.availHeight;
   var winw    = w + 32;
   var winh    = h + 32;


   if (w == 0 || w > screenw) w = screenw;
   if (h == 0 || h > screenh) h = screenh;

   var posx = (screenw / 2) - (winw / 2);
   var posy = (screenh / 2) - (winh / 2);

   var mywin = window.open("./?show=images&oid="+oid+"&imgid="+id+"&maxheight="+h, "objimageswin", "top="+posy+",left="+posx+",width="+winw+",height="+winh+",menubar=no,locationbar=no,statusbar=no,resizable=yes,toolbar=no,dependent=yes,scrollbars=yes");

}