複選框全選、取消全選

<%@ Control Language="c#" AutoEventWireup="false" Codebehind="Main.ascx.cs" Inherits="CSharpWorkflow.UserControl.Apply.Main" TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var checkflag = "false";
function check(field) {
if (checkflag == "false") {
for (i = 0; i < field.length; i++) {
field[i].checked = true;}
checkflag = "true";
return "Uncheck All"; }
else {
for (i = 0; i < field.length; i++) {
field[i].checked = false; }
checkflag = "false";
return "Check All"; }
}
//  End -->
</script>
<form name=myform action="" method=post>
<table border="0" width="100%" cellspacing="0" cellpadding="3" id="Table1">
 <tr>
  <td><img src="../../images/@stockin.gif" WIDTH="22" HEIGHT="20"><b>單位管理</b></td>
 </tr>
</table>
<table>
<tr><td>
<b>軟件係數調查1：</b><input type=checkbox onClick="check(this.form.list)"> <br>

<input type=checkbox name=list value="1">軟件的界面<br>
<input type=checkbox name=list value="2">特效很多<br>
<input type=checkbox name=list value="3">分類詳細<br>
<input type=checkbox name=list value="4">完全免費<br>
<input type=checkbox name=list value="5">特效很實用<br>
<input type=checkbox name=list value="6">更新速度快<br>                                                 

</td></tr>

</table>
</form>