function tourZoomImage(imageNum)
{
   var imageWidth  = 0;
   var imageHeight = 0;

   switch(imageNum) {
      case 1:
      case 2:
	 imageWidth  = 534;
	 imageHeight = 647;
	 break;
      case 3:
	 imageWidth  = 534;
	 imageHeight = 646;
	 break;
      case 4:
	 imageWidth  = 680;
	 imageHeight = 605;
	 break;
      case 5:
	 imageWidth  = 471;
	 imageHeight = 493;
	 break;
      case 6:
	 imageWidth  = 655;
	 imageHeight = 533;
	 break;
//      case "6a":  // not presently used, but maybe in the future
//	 imageWidth  = 472;
//	 imageHeight = 494;
//	 break;
      case 7:
	 imageWidth  = 602;
	 imageHeight = 699;
	 break;
      case 8:
	 imageWidth  = 534;
	 imageHeight = 472;
	 break;

      default:
	 return;
   }

   var width  = imageWidth  + 10;
   var height = imageHeight + 45;

   var windowArgs = "width=" + width + ",height=" + height + ",left=60,top=10";

   window.open("include/tour-zoom.jsp?" + imageNum, "screenshot", windowArgs);
}