// Detect if browser is Netscape 3 + or IE 4 +.
bName = navigator.appName;
bVer = parseInt(navigator.appVersion);
    if ((bName == "Netscape" && bVer >= 3) || 
        (bName == "Microsoft Internet Explorer" && bVer >= 4)) br = "n3"; 
    else br = "n2";

// Rollover code 
    if (br== "n3") { 
    img1on = new Image();         
    img1on.src = "images/map_on.gif";


    img1off = new Image();          
    img1off.src = "images/map_off.gif"; 

	
    }
// Function to "activate" images.
function imgAct(imgName) {
    if (br == "n3") {
    document[imgName].src = eval(imgName + "on.src");
    }
}

// Function to "deactivate" images.
function imgInact(imgName) {
    if (br == "n3") {
    document[imgName].src = eval(imgName + "off.src");
    }
}