简单实现jQuery多选框功能

<input type="checkbox" id="c1">全选/全不选<br>
兴趣爱好：<br>
<input type="checkbox" name="interst" value="basketball">篮球
<input type="checkbox" name="interst" value="football">足球
<input type="checkbox" name="interst" value="bedminton">羽毛球<br>
<input type="button" id="b1" value="全选">
<input type="button" id="b2" value="全不选">
<input type="button" id="b3" value="反选">
<input type="button" id="b4" value="显示">

$("#c1").click(function(){
if(this.checked){
  $("input[name='interst']").attr("checked","checked");
}else{
  //$("input[name='interst']").attr("checked",""); //等价于
  $("input[name='interst']").removeAttr("checked");
}
});

$("#b1").click(function(){
  $("input[name='interst']").attr("checked","checked");
});

$("#b2").click(function(){
  $("input[name='interst']").attr("checked","");
});

$("#b3").click(function(){
  $("input[name='interst']").each(function(){
  if(this.checked){
    this.checked="";
  }else{
    this.checked="checked";
  }
  });
});

$("#b4").click(function(){
$("input[name='interst']:checked").each(function(){
  alert(this.value);
});
});