//Jquery 滚动插件
(function($){ 
$.fn.extend({
	Scroll:function(opt,callback){
		if(!opt) var opt={};
		var _this=this.eq(0).find("ul:first");
		var lineH=_this.find("li:first").height();
		var line = opt.line ? parseInt(opt.line,10) : parseInt(this.height()/lineH,10);
		var speed = opt.speed ? parseInt(opt.speed,10) : 500;
		var timer = opt.timer ? parseInt(opt.timer,10) : 3000;
		if(line==0) line=1; 
		var upHeight=0-line*lineH; 
		var scrollUp=function(){ 
			_this.animate({ 
				marginTop:upHeight 
			},speed,function(){ 
				for(i=1;i<=line;i++){ 
					_this.find("li:first").appendTo(_this); 
				}
				_this.css({marginTop:0}); 
			});
		}
		var timerID = window.setInterval(scrollUp,timer);
		var autoPlay = function(){
			if(timer) timerID = window.setInterval(scrollUp,timer);
        };
		var autoStop = function(){
			if(timer) window.clearInterval(timerID);
		};
		_this.hover(autoStop,autoPlay).mouseout();
	}
});
})(jQuery);