if (document.images) {
                var b1a = new Image();
                b1a.src = "art/b1.gif";
                var b2a = new Image();
                b2a.src = "art/b2.gif";
                var b3a = new Image();
                b3a.src = "art/b3.gif";
                var b4a = new Image();
                b4a.src = "art/b4.gif";
                var b5a = new Image();
                b5a.src = "art/b5.gif";
                var b6a = new Image();
                b6a.src = "art/b6.gif";

                
                //buttons off
                var b1b = new Image();
                b1b.src = "art/b1_1.gif";
                var b2b = new Image();
                b2b.src = "art/b2_1.gif";
                var b3b = new Image();
                b3b.src = "art/b3_1.gif";
                var b4b = new Image();
                b4b.src = "art/b4_1.gif";
                var b5b = new Image();
                b5b.src = "art/b5_1.gif";
                var b6b = new Image();
                b6b.src = "art/b6_1.gif";
 
                }
function act(imgName) {
                if (document.images) 
                document[imgName].src = eval(imgName + "b.src");
              }

function inact(imgName) {
                if (document.images)
                  document[imgName].src = eval(imgName + "a.src");
              }