非常不错的一个javascript 类

    } else if (document.body) {// all other Explorers
        yScroll = document.body.scrollTop;
    }
    var getPageSize = new Array(pWidth,pHeight,winWidth,winHeight,yScroll) 
    return getPageSize;
}


jscc.widgets = {/**/};
jscc.widgets.fixedsidebar = {
    fixedHeight:0,
    oldScrolltop:0,
    init: function(){
        if (!document.getElementById("sidebar")) return;
        jscc.addEvent(window,"scroll",function(e){jscc.widgets.fixedsidebar.setFixed()});
        jscc.addEvent(window,"resize",function(e){jscc.widgets.fixedsidebar.setFixed()});
        this.fixedHeight=document.getElementById("sidebar").offsetTop;
        this.setFixed();
    },
    setFixed:function(){
        var sidebar=document.getElementById("sidebar");
        var ref=document.getElementById("main");
        var s_t=sidebar.offsetTop;
        var s_h=sidebar.offsetHeight;
        var s_th=s_t+s_h;
        var r_th=ref.offsetTop+ref.offsetHeight;
        var d_st;
        if(document.documentElement.scrollTop){
            d_st=document.documentElement.scrollTop;
        }
        else{
            d_st=document.body.scrollTop
            }
        if(r_th>(s_t+s_h)){
            var seHeight=0; 
            if (self.innerHeight) {    seHeight = self.innerHeight;} else if (document.documentElement && document.documentElement.clientHeight) {    seHeight = document.documentElement.clientHeight;} else if (document.body) {seHeight = document.body.clientHeight;}
            try{