MutuallyExclusiveCheckBox控件实现复选框互斥功能
属性列表：
TargetControlID:被控制控件的ID
Key: 区分互斥复选框的键值（两个互斥复选框的要一样）
实例解析一、简单实现
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
</div>
<asp:CheckBox ID="net" runat="server" Text="net" />
<asp:CheckBox ID="jsp" runat="server" Text="jsp" /><br />
<asp:CheckBox ID="aspnet" runat="server" Text="aspnet"/>
<asp:CheckBox ID="java" runat="server" Text="java" />
<cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender1" runat="server"
Key="one" TargetControlID="net">
</cc1:MutuallyExclusiveCheckBoxExtender>
<cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender2" runat="server"
Key="two" TargetControlID="jsp">
</cc1:MutuallyExclusiveCheckBoxExtender>
<cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender3" runat="server"
TargetControlID="aspnet" Key="two">
</cc1:MutuallyExclusiveCheckBoxExtender>
<cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender4" runat="server" TargetControlID="java" Key="one">
</cc1:MutuallyExclusiveCheckBoxExtender>
</form>