function switchzjtj()
{
     $(document).ready(function(){
	  _roll_init();	
	 
     })

      var _roll_initWidth;
      var _roll_speed = 2000;
      var _roll = setInterval(_roll_left, _roll_speed);
      $('#roll .roll_warp').hover(function(){clearInterval(_roll)}, function(){_roll = setInterval(_roll_left, _roll_speed)});

 
    function _roll_init(){
	//初始宽度
	var initElems = $('.roll_move .e');
	_roll_initWidth = initElems.outerWidth(true) * initElems.size();
	//首尾插入移动子元素
	var elemHtml = $('.roll_move').html();
	$('.roll_move').prepend(elemHtml);//head
	$('.roll_move').append(elemHtml);//foot
	//设置移动元素宽度
	var moveElemWidth = _roll_initWidth * 3;
	$('.roll_move').css('width', moveElemWidth);
	//设置包裹元素的scrollLeft
	$('.roll_warp').attr('scrollLeft', _roll_initWidth);
      }


function _roll_left(){
	var warpElem = document.getElementById('roll_warp');
	$('.roll_warp').animate(
		{scrollLeft : warpElem.scrollLeft + 320},
		{duration : 'slow', complete : function(){if(warpElem.scrollLeft == _roll_initWidth * 2){warpElem.scrollLeft = _roll_initWidth}}}
	)
}





}