function SetActiveMenuItem(index){
    var menuElements = document.getElementById("mainMenu");

  
    var menuItem = menuElements.firstChild;
    var currentIndex = 0;
    while(menuItem){
        if(menuItem.nodeType == 1){

            
            menuItem.firstChild.removeAttribute("class"); 
            
            if(currentIndex == index){
                if(index > 0){
                    menuItem.firstChild.setAttribute("class", "active");                  
                }
                else{
                    menuItem.firstChild.setAttribute("class", "defaultActive");
                }
            }
            
           currentIndex++;  
        }
        
        menuItem = menuItem.nextSibling; 
    
    }
    
}

function getIEVersionNumber() {
    var ua = navigator.appVersion;
    var MSIEOffset = ua.indexOf("MSIE");

    if (MSIEOffset == -1) {
        return 0;
    } else {
        return parseFloat(ua.substring(MSIEOffset + 5, ua.indexOf(";", MSIEOffset)));
    }
}

//This function is a lot faster than the first version.
function SetActiveMenuItem_V2(index){
    var menuElements = document.getElementById("mainMenu");
    var linkElements = menuElements.getElementsByTagName("a");
    var ie = 0;
    var ieVersion = 0;
    var attrName = "class";

    if (navigator.appName == "Microsoft Internet Explorer") {
        ie = 1;
        ieVersion = getIEVersionNumber();
    }


    if (ie > 0) {
        if (ieVersion < 8) {
            attrName = "className";
        }
    }

    //Clear any previous active links
    for (var i = 0; i < linkElements.length; i++) {
        linkElements[i].removeAttribute(attrName);
    }
    

    var menuItem = linkElements[index];

    if (index > 0) {

        menuItem.setAttribute(attrName, "active");
    }
    else {
        menuItem.setAttribute(attrName, "defaultActive");
    }


}