browserName = navigator.appName; 
    browserVer = parseInt(navigator.appVersion);
    if (browserName == "Netscape" && browserVer >= 3){
    init = "net";
    }
    else{
    init = "ie";
    }
    if ((init == "net")||((init == "ie")&&(browserVer >= 4))){
    image11on = new Image();
    image11on.src = "botons/volve2.jpg";
    image11off = new Image();
    image11off.src = "botons/volve.jpg";


    

    }
    function img_on(imgName)
    {
    if (((init == "net")&&(browserVer >=3))||((init == "ie")&&(browserVer >= 4))){
    imgOn = eval(imgName + "on.src");
    document[imgName].src = imgOn;
    }
    }
    function img_off(imgName)
    {
    if (((init == "net")&&(browserVer >=3))||((init == "ie")&&(browserVer >= 4))){
    imgOff = eval(imgName + "off.src");
    document[imgName].src = imgOff;
    }
    }