bName = navigator.appName;
    bVer = parseInt(navigator.appVersion);
    ver = "other";
if ((bName == "Netscape" && !(bVer < 3)) 
 || (bName == "Microsoft Internet Explorer" && !(bVer < 4))) ver = "good"; 

if (ver == "good") {
        nav01on = new Image(88,36);
        nav01on.src = "/espanol/images/helpon.gif";
        nav01off = new Image(88,36);
        nav01off.src = "/espanol/images/helpoff.gif";
        nav02on = new Image(88,36);
        nav02on.src = "/espanol/images/lookingon.gif";
        nav02off = new Image(88,36);
        nav02off.src = "/espanol/images/lookingoff.gif";
        nav03on = new Image(88,36);
        nav03on.src = "/espanol/images/askshareon.gif";
        nav03off = new Image(88,36);
        nav03off.src = "/espanol/images/askshareoff.gif";
        nav04on = new Image(88,36);
        nav04on.src = "/espanol/images/bullitenon.gif";
        nav04off = new Image(88,36);
        nav04off.src = "/espanol/images/bullitenoff.gif";
        nav05on = new Image(88,36);
        nav05on.src = "/espanol/images/teacheron.gif";
        nav05off = new Image(88,36);
        nav05off.src = "/espanol/images/teacheroff.gif";
        nav06on = new Image(88,36);
        nav06on.src = "/espanol/images/homeon.gif";
        nav06off = new Image(88,36);
        nav06off.src = "/espanol/images/homeoff.gif";
}

function rollon(imgName) {
    if (ver == "good") {
        imgOn = eval(imgName + "on.src");
        document[imgName].src = imgOn;
    }
}

function rolloff(imgName) {
    if (ver == "good") {
        document[imgName].src = eval(imgName + "off.src");
    }
}