function picRoll_2(config){
	var defaultConfig = {
		eleFather: null,  //容器标签 父元素 最外围标签  
		imgWidth:0,
		showImgNum:0,
		rollLeft: null,   //向左转标签
		rollRight: null,  //向右转标签
		time:3000         //图片切换时间间隔，默认3000毫秒
	}
	config = $.extend({},defaultConfig,config);
	var pointer = 0;
	var $imgUl = $(config.eleFather).children('ul');//检索获取图片ul列表
	var imgWidth = config.imgWidth;
	var imgNum = $imgUl.children('li').length;
	var arrInter = [];
	//根据图片数量自匹配imgUl的宽
	var startLeft = -imgWidth*imgNum;
	$imgUl.width(imgWidth*imgNum*2).append($imgUl.html()).css('left',startLeft);
	//定时器
	arrInter.push(setInterval(function(){_move('-')},config.time));
	$(config.eleFather).mouseover(function(){
		_clearInter(arrInter);
	}).mouseout(function(){
		arrInter.push(setInterval(function(){_move('-')},config.time));
	})
	//左右点击按钮的hover透明度效果
	var opa = $(config.rollLeft).css('opacity');
	$(config.rollLeft+","+config.rollRight).hover(function(){
		$(this).css('opacity',1);
		_clearInter(arrInter);
	},function(){
		$(this).css('opacity',opa);
		arrInter.push(setInterval(function(){_move('-')},config.time));
	})
	//向左，向右滚动点击效果
	$(config.rollLeft).click(function(){
		_move('+');
	})
	$(config.rollRight).click(function(){
		_move('-');
	})
	//底部缩略图点击效果
	function _move(style){
		$imgUl.stop(true,true)
		var imgUlLeft = parseInt($imgUl.css('left'));
		console.log(startLeft+config.showImgNum*imgWidth)
		if(imgUlLeft<=startLeft-(imgNum-config.showImgNum)*imgWidth){
			$imgUl.css('left',startLeft+config.showImgNum*imgWidth+'px');
		}
		if(imgUlLeft>=0){
			$imgUl.css('left',startLeft);
		}
		$imgUl.animate({left: style+'='+imgWidth+'px'},'slow');
	}
	function _clearInter(arrInter){
		for (var i = arrInter.length - 1; i >= 0; i--) {
			clearInterval(arrInter[i]);
		}
	}
	
}