[原]全选或全不选

    <input type="button" name="name" value="全选" id="btnAll" />
    <input type="button" name="name" value="全不选" id="btnNoAll" />
    <input type="button" name="name" value="反选" id="btnFanXuan" />
<fieldset>
<legend>歌曲</legend>
   <input type="checkbox" name="name" value="1" />真的爱你
     <input type="checkbox" name="name" value="1" />the show
      <input type="checkbox" name="name" value="1" />我的太阳
       <input type="checkbox" name="name" value="1" />再回首<br />
        <input type="checkbox" name="name" value="1" />光辉岁月
         <input type="checkbox" name="name" value="1" />好久不见
          <input type="checkbox" name="name" value="1" />周杰棍的双杰伦
</fieldset>

window.onload = function () {

            //歌曲列表 （CheckBox+Label）全选、全不选、反选，只针对一个层中，div.getElementsByTagName("input")，再判断type='checkbox'的项，checked="checked"。

            document.getElementById('btnAll').onclick = function () {

                var chks = document.getElementsByTagName('input');
                for (var i = 0; i < chks.length; i++) {
                    if (chks[i].type == 'checkbox') {
                        chks[i].checked = true;
                    }
                }
            };

            document.getElementById('btnNoAll').onclick = function () {

                var chks = document.getElementsByTagName('input');
                for (var i = 0; i < chks.length; i++) {
                    if (chks[i].type == 'checkbox') {
                        chks[i].checked = false;
                    }
                }
            };

            document.getElementById('btnFanXuan').onclick = function () {

                var chks = document.getElementsByTagName('input');
                for (var i = 0; i < chks.length; i++) {
                    if (chks[i].type == 'checkbox') {
                        chks[i].checked = !chks[i].checked;
                    }
                }
            };
        };