function showContent(url, pres, session, cw, ch) {
        if (session != "") url = url + "?session=" + session;
	var w, h, l, t;
	if (pres) {
	  w = 0.96 * screen.width;
	  h = 0.76 * screen.height;
	  l = 0;
	  t = 0;
	} else {
	  if (cw > 0 && ch > 0) {
	    if (cw <= screen.width) {
              w = cw;
              h = w * ch /cw;
            }
            if (h > screen.height) {
              h = screen.height;
              w = h * cw / ch;
            }
	  } else {
	    w = 0.4 * screen.width;
	    h = 0.3 * screen.height;
	  }

          l = (screen.width - w) / 2;
          t = (screen.height - h) / 2;
        }
	var options = "toolbar=0,status=0,location=0,resizable=1,left=" + l + ",top=" + t + ",width=" + w + ",height=" + h;
	var win = open(url, "", options);
    }