$(window).bind('scroll',function(event) {

    var wh1=$(window).height()

    var wh2=$(document).height()

    alert(wh1+"+"+wh2);

    if($(document).height() > $(window).height())

    {

    if($(window).scrollTop() == $(document).height() - $(window).height()){

    alert("123");

    //加载内容 

    }

    }

    });

});