browserName = navigator.appName;
     browserVer = parseInt(navigator.appVersion);
             if (browserName == "Netscape" || browserVer >= 3) version = "n3";
             else version = "n2";

             if (version == "n3") {
             toc1on = new Image();
             toc1on.src = "images/add_01a.gif";
             toc2on = new Image();
             toc2on.src = "images/add_03a.gif";
             toc3on = new Image();
             toc3on.src = "images/add_05a.gif";

             toc1off = new Image();
             toc1off.src = "images/add_01.gif";
             toc2off = new Image();
             toc2off.src = "images/add_03.gif";
             toc3off = new Image();
             toc3off.src = "images/add_05.gif";
		 
            }
function img_act(imgName) {
             if (version == "n3") {
             imgOn = eval(imgName + "on.src");
             document [imgName].src = imgOn;
             }
     }
function img_inact(imgName) {
             if (version == "n3") {
             imgOff = eval(imgName + "off.src");
             document [imgName].src = imgOff;
             }
     }