var weescroller = function(idUl, options) {

    var self = this;  	

  	this.pausetimer = null;

  	this.steptimer = null;

    this.oUl = $(idUl);

    this.oOUl = this.oUl.clone();

    this.CTL = 0;

    //设置默认属性

   	this.options = {	//默认值

   		row: 5,			//显示行数

  		time: 15,		//速度(越大越慢)

      	pause: 2000,	//停顿时间

      	direct: 0,		//0向上,1向下,2向左,3向右

   	};

   	this.options = $.extend(self.options, options || {});   	

    //向下

    this.Next = function() {

    	if (!self.canscroll) return false;

    	clearTimeout(self.pausetimer);

    	clearInterval(self.steptimer);

    	var height = self.oUl.find("li:first").height();

    	self.steptimer = setInterval(function(){

    		if (self.CTL >= height) {

    			self.CTL = 0;

    			clearInterval(self.steptimer);

    			self.oUl.find("li:first").appendTo(self.oUl);

    			self.oUl.get(0).scrollTop = 0;

    			self.pausetimer = setTimeout(self.Next, self.options.pause);

    		} else {

    			self.CTL++;

    			self.oUl.get(0).scrollTop++;

    		}

    	}, self.options.time);

    }

    //向左

    this.Left = function() {

    	if (!self.canscroll) return false;

    	clearTimeout(self.pausetimer);

    	clearInterval(self.steptimer);

    	var width = self.oUl.find("li:first").width();

    	self.steptimer = setInterval(function(){

    		if (self.CTL >= width) {

    			self.CTL = 0;

    			clearInterval(self.steptimer);

    			self.oUl.find("li:first").appendTo(self.oUl);

    			self.oUl.scrollLeft = 0;

    			self.pausetimer = setTimeout(self.Left, self.options.pause);

    		} else {

    			self.CTL++;

    			self.oUl.scrollLeft--;

    		}

    	}, self.options.time);

    }

    //上一个

    this.GoPrev = function() {

    	if (!self.canscroll) return false;

    	if (self.CTL > 0) {

    		self.CTL = 0;

    		self.oUl.get(0).scrollTop = 0;

    	} else {

    		self.oUl.find("li:last").prependTo(self.oUl);

    	}

    }

    //跳到第一个

    this.GoFirst = function() {

    	if (!self.canscroll) return false;

    	while(!self.oUl.find("li:first").hasClass("first")) {

    		this.GoPrev();

    	}

    }

  	//停止

  	this.Stop = function() {

    	clearTimeout(self.pausetimer);

    	clearInterval(self.steptimer);

  	}

    //增加一个LI

    this.Append = function(li, limit, type) {

    	limit = limit - 1;

    	self.oOUl.find(".first").removeClass("first").before(li);

    	if (type == 'new') {

    		self.oOUl.find(".speaker_new").remove();

    		self.oOUl.find("li.mine:gt("+(limit)+")").remove();

    	} else {

    		self.oOUl.find(".speaker_user").remove();

    		self.oOUl.find(".first").nextAll("li:gt("+(limit-1)+")").find(".speaker_new").remove();

    	}

    	self.oOUl.find("li.nohas").remove();

    	self.Stop();

    	self.Start();

    }

    this.Start = function() {

	    //数据是否够滚动

	    self.canscroll = (self.oOUl.find('li').length > self.options.row);    

	  	if (self.canscroll) {

	   		self.oUl.html(self.oOUl.html()+self.oOUl.html());

	   	} else {

	   		self.oUl.html(self.oOUl.html());

	   	}

	  	switch (self.options.direct) {

	  		case 0 : 

	  		   	self.pausetimer = setTimeout(self.Next, self.options.pause);

	  		   	break;

	  		case 1 :

	  			self.pausetimer = setTimeout(self.Prev, self.options.pause);

	  		   	break;

	  		case 2 :

	  			self.pausetimer = setTimeout(self.Left, self.options.pause);

	  		   	break;

	  		case 3 :

	  			self.pausetimer = setTimeout(self.Right, self.options.pause);

	  		   	break;

	  	}

   	}

   	this.oUl.mouseover(function(){self.Stop();});

   	this.oUl.mouseout(function(){self.Next();});

   	this.Start();   	

}