JS页面滚动动态加载数据，页面下拉自动加载内容

	//<!-- 页面滚动动态加载数据，页面下拉自动加载内容 -->
	$(window).scroll(function(){          
		totalheight =parseFloat($(window).scrollTop())+ parseFloat($(window).height());  
	  if(($(document).height()/2) <= totalheight ) {  //有滚动条 且滚动到触发点(一半)
	     next();
	  }  
	});  
	$(window).on('mousewheel', function(event) { //手机不支持
		totalheight =parseFloat($(window).scrollTop())+ parseFloat($(window).height());
		if(totalheight==$(document).height()) //无滚动条
		{
		if(event.originalEvent.wheelDelta<0) //且 向下滚动
		   		next();
		}
	});