var is_opera =  navigator.userAgent.indexOf('Opera') > -1;
var is_safari = navigator.userAgent.indexOf('AppleWebKit/') > -1;
var is_chrome = navigator.userAgent.indexOf('Chrome') > -1;
var is_firefox = navigator.userAgent.indexOf('Firefox') > -1;
var is_mac = navigator.platform.toLowerCase().indexOf('mac') > -1;
var is_linux = navigator.platform.toLowerCase().indexOf('linux') > -1;
var ie6 = false;
var ie7 = false;
var ie8 = false;

function init() {
    if(ie6 || ie7) {
        
        var navigation_el = document.getElementById('navigation');
        var level_1_items = navigation_el.getElementsByTagName('li');

        var il = level_1_items.length;
        for(var i = 0; i < il; i++) {
            var current_el = level_1_items[i];
            
            var has_subitem = current_el.getElementsByTagName('ul').length > 0;
            if(!has_subitem) continue;
            
            if(current_el.nodeName.toLowerCase() == "li") {
                current_el.onmouseover = function() {
                    if(this.className.indexOf('active') != -1) {
                        this.className += " active-over";
                    } else {
                        this.className += " over";
                    }
                    
                }
    
                current_el.onmouseout = function() {
                    this.className=this.className.replace(" active-over", "");
                    this.className=this.className.replace(" over", "");
                }
                  
            }
        }
    }
}