如何使jquery垂直滑块继续移动

Question

我是新来的，我真的需要你的建议。我有一个jquery垂直滑块，我有两个问题：

1. 它在最后一行之后停止

2. 当我将鼠标放在一个单元格上时，它不会停止。

以下是代码：

(function($) {
  $.fn.vertigo = function(options) {

    $(this).addClass("vertigo");
    var list = $('.vertigo li');
    var totallist = list.length;

    $(this).after('<a href="#pre" class="btn-pre"><img src="prev.png"/></a> <a href="#next" class="btn-next"><img src="next.png"/></a>');
    $('.vertigo li').each(function(i) {
        $(this).addClass("item"+(i+1));
    });

    var total = 1;

    // Settings
    var settings = $.extend({
        play  : true,
        timer : 1000
    }, options);

    if ( settings.play ) {
        var playx = settings.play;  
    }       
    if ( settings.timer ) {
        var timerx = settings.timer;    
    }

    if(playx == true){
        setInterval(function() {

            if ( total <= (totallist - 1)) {
                var nlisth = $('.item'+total).outerHeight();
                $('.vertigo li').animate({'top':'-='+nlisth+'px'}); 
                total++;
                //console.log(total);
            }else{

                $('.vertigo li')=1;


            }
        }, timerx);
    }

    $('.btn-pre').click(function(){
        var plisth = $('.item'+(total-1)).outerHeight();
        if ( total !== 1 && total <= totallist) {
            total--;
            $('.vertigo li').animate({'top':'+='+plisth+'px'});
        }
    });

    $('.btn-next').click(function(){
        var nlisth = $('.item'+total).outerHeight();
        if ( total <= (totallist - 1)) {
            total++;
            $('.vertigo li').animate({'top':'-='+nlisth+'px'});
        }
    }); 

  }

  return false;

}(jQuery));