Full selection of jquery, no selection, reverse selection

Full selection of jquery, not selected, reversed:

<%@ Page language="C #"autoeventwireup="true"Codebehind="Jqueryselect.aspx.cs"inherits="Webapplication9.jqueryselect"%><! DOCTYPE html>"http://www.w3.org/1999/xhtml">"Server"><meta http-equiv="Content-type"Content="text/html; Charset=utf-8"/> <title></title> <script src="Scripts/jquery-1.7.1.js"></script> <script type="Text/javascript">$ (function () {$ ("#selectAll"). Click (function () {//Select All$("#playList: CheckBox"). attr ("checked",true);            }); $("#unSelect"). Click (function () {//all do not choose$("#playList: CheckBox"). attr ("checked",false);            }); $("#reverse"). Click (function () {//Inverse Selection$("#playList: CheckBox"). each (function () {$ ( This). attr ("checked", !$( This). attr ("checked"));            });        });    }); </script>"playList"> <input type="checkbox"Value="Song 1"/> Song 1<br/> <input type="checkbox"Value="Song 2"/> Song 2<br/> <input type="checkbox"Value="Song 3"/> Song 3<br/> <input type="checkbox"Value="Song 4"/> Song 4<br/> <input type="checkbox"Value="Song 5"/> Song 5<br/> <input type="checkbox"Value="Song 6"/>Song 6</div> <input type="Button"Value="Select All"Id="SelectAll"/> <input type="Button"Value="all do not choose"Id="unselect"/> <input type="Button"Value="Inverse Selection"Id="Reverse"/></body>
Full selection of jquery, no selection, reverse selection