function navbar_toggleHover(item, isHover) {
    var classNamesStr = item.className;
    
    if (classNamesStr == null) {
        return;
    }
    
    var classNames = item.className.split(' ');
    var index = null;
    for (var i in classNames) {
        if (classNames[i] == "hover") {
            index = i;
        }
    }
    
    if (index == null) {
        if (isHover == true) {
        classNamesStr += " hover";
        }
    } else {
        classNames.splice(index, 1);
        classNamesStr = classNames.join(' ');
    }
    
    item.className = classNamesStr;
}