browserName = navigator.appName;
     browserVer = parseInt(navigator.appVersion);
             if ((browserName == "Netscape" && browserVer >= 3) || (browserName == "Microsoft Internet Explorer" && browserVer >= 4)) version = "n3";
             else version = "n2";
            
             if (version == "n3") {
             img = "icons";
             tocoff = new Image(35,600);
             tocoff.src = "./images/index-off-n.gif";

             toc1on  = new Image(35,600);
             toc1on.src = "./images/index-off-n.gif";
             toc2on  = new Image(35,600);
             toc2on.src = "./images/duct-off-n.gif";
             toc3on = new Image(35,600);
             toc3on.src = "./images/heater-off-n.gif";
             toc4on = new Image(35,600);
             toc4on.src = "./images/cooling-off-n.gif";
             toc5on = new Image(35,600);
             toc5on.src = "./images/dehumidifier-off-n.gif";
             toc6on = new Image(35,600);
             toc6on.src = "./images/login-off-n.gif";
         
	     }

     function img_act(imgName) {
             if (version == "n3") {
             imgOn = eval("toc" + imgName + "on.src");
             document ["toc"].src = imgOn;
             }
     }

     function img_inact(imgName) {
             if (version == "n3") {
             imgOff = eval("tocoff.src");
             document ["toc"].src = imgOff;
             }
     }