JS:

<script>
	$('#change_item_list .hot_susume_item_box').hide();//先全部隐藏
	
	//产生不重复随机排序数组
	function randomIndex(n){
    var i, j, tmp, a = new Array(n);
    a[0] = 0;
    for(i = n-1; i > 0; i--) {
        j = Math.floor(Math.random() * (i+1));
        tmp = a[i] || i;
        a[i] = a[j] || j;
        a[j] = tmp;
    };
    return a;
    }
	
	//一共有多少个项目
    var hot_item_nums = $('#change_item_list .hot_susume_item_box').length;
    hot_item_arr = randomIndex(hot_item_nums);
	radowm_Show()
	
	//对应显示
	function radowm_Show(){
	   var new_hot_item_arr=hot_item_arr.slice(0, 5)
       var hot_max_nums = Math.max.apply(null, new_hot_item_arr);//最大值
       var arrvalue;//用于存放取出的数组的值
        for(var i=0;i<5;i++){
        arrvalue=new_hot_item_arr[i];//数组的索引是从0开始的.
	     $('#change_item_list .hot_susume_item_box').eq(arrvalue).show();
	     if(i==4){
		 $('#change_item_list .hot_susume_item_box').eq(hot_max_nums).addClass('hot_item_last_one')
		 
	     }
         
       }
	}
	/*点击事件*/
	$('#hot_change').click(function(){
		$('#change_item_list .hot_susume_item_box.hot_item_last_one').removeClass('hot_item_last_one')
		$('#change_item_list .hot_susume_item_box').hide();
		var hot_item_nums = $('#change_item_list .hot_susume_item_box').length;
        hot_item_arr = randomIndex(hot_item_nums);
	    radowm_Show()
	});
</script>