js选择checkbox

<pre name="code" class="html"><p><input type="checkbox" name="love" onclick="selectAllNo()">全选/全不选</p><p><input type="checkbox" name="love">篮球</p><p><input type="checkbox" name="love">足球</p><p><input type="checkbox" name="love">乒乓球</p><input type="button" value="全选" onclick="selectAll()"><input type="button" value="全不选" onclick="selectNo()"><input type="button" value="反选" onclick="reserve()">

var check=document.getElementsByName("love");if(check[0].checked){for (var i = 1; i < check.length; i++) {check[i].checked=true;};}else{for (var i = 1; i < check.length; i++) {check[i].checked=false;};}function selectAll () {for (var i = 0; i < check.length; i++) {check[i].checked=true;};}function selectNo () {for (var i = 0; i < check.length; i++) {check[i].checked=false;};}function reserve () {for (var i = 0; i < check.length; i++) {check[i].checked=(check[i].checked==true)?false:true;};}function selectAllNo () {if(check[0].checked==true){selectAll();}else{selectNo();}}