我实现的总是左右,想换成自右向左的,要怎么修改代码呢
<script src="jquery1.2.6.js"></script>
<script>
$(document).ready(function(){
var ctrl=true;
$('#bt1').click(function(){
 if(ctrl){
   $("#list1").animate({width:"0px"},'slow'); 
   $("#list2").animate({width:"200px"},'slow');
   ctrl=false;
  }else{
   $("#list1").animate({width:"200px"},'slow'); 
   $("#list2").animate({width:"0px"},'slow');
   ctrl=true;
  }
});
});
</script>
</head><body>
<input type="button" value="按钮1" id="bt1"/>
<div style="width:200px; height:200px; overflow:hidden;" id="wai">
<div style="width:400px;" id="mid">
<div style="background:#FF0000; width:200px; height:200px; float:left;" id="list1"></div>
<div style="background:#0000FF; width:200px; height:200px; float:left;" id="list2"></div>
</div>
</div>
</body>
</html>