num = 20;
is_loading = false;
$(function(){
$(window).scroll(function(){
var scrollTop = $(this).scrollTop();
var scrollHeight = $(document).height();
var windowHeight = $(this).height();
if(scrollTop + windowHeight >= scrollHeight - 200 && !is_loading){
is_loading = true;
$('#lodingPic').show();
var id="791";
setTimeout("is_loading = false", 2000);
$.getJSON("http://m.cheaa.com/ajax_list_more.php?action=more_new&id="+id+"&num="+num,function(a){
$('#newsList').append(a);
num += 20;
$('#lodingPic').hide();
});
}
});
});