function addCss(element,cssName){ 
        var element,cssName; 
        if (!element.className || element.className == cssName){ 
            element.className = cssName; 
        } 
        else{ 
            element.className = element.className + " " + cssName; 
        } 
    } 
    function removeCss(element,cssName){ 
        var element,cssName; 
        var oldCss = element.className; 
        var cssList = oldCss.split(" "); 
        for(var i = 0;i < cssList.length;i++){ 
            if (cssList[i] == cssName) { 
                cssList[i] = ""; 
                break; 
            } 
        } 
        element.className = cssList.join(" "); 
    }