// 添加类

function addClass(node,className){

                var reg=new RegExp("\\b"+className+"\\b");

                if(!reg.test(node.className)){

                    node.className +=(" "+className);

                }

}

 

// 移除类

function removeClass(node,className){

                if(node.className){

                    var reg=new RegExp("\\b"+className+"\\b");

                    var classes = node.className;

                    node.className=classes.replace(reg,"");

                    if(/^\s*$/g.test(node.className)){

                        node.removeAttribute("class");

                    }

                }else{

                    node.removeAttribute("class");

                }

}