ajaxToolkit:FilteredTextBoxExtender的使用方法

vs.2005有ajaxToolkit:FilteredTextBoxExtender的使用方法吗,这个控件哪里来的,我这里没有啊
--------------------编程问答-------------------- <table border="0">
            <tr>
                <td>Only digits are allowed here:</td>
                <td><asp:TextBox ID="TextBox1" runat="server" /></td>
            </tr>
            <tr>
            <td>Only lower-case letters are allowed here:</td>
                <td><asp:TextBox ID="TextBox2" runat="server" /></td>
            </tr>
            <tr>
            <td>Only math symbols (+,-,*,/,=,.) and numbers:</td>
                <td><asp:TextBox ID="TextBox3" runat="server" /></td>
            </tr>
            <tr>
            <td>No digits allowed in this textbox:</td>
                <td><asp:TextBox ID="TextBox4" runat="server" /></td>
            </tr>
        </table>

        <ajaxToolkit:FilteredTextBoxExtender
           ID="FilteredTextBoxExtender1"
           runat="server"
           TargetControlID="TextBox1"
           FilterType="Numbers" />

        <ajaxToolkit:FilteredTextBoxExtender
            ID="FilteredTextBoxExtender2"
            runat="server"
            TargetControlID="TextBox2"
            FilterType="LowercaseLetters" />

        <ajaxToolkit:FilteredTextBoxExtender
            ID="FilteredTextBoxExtender3"
            runat="server"
            TargetControlID="TextBox3"
            FilterType="Custom, Numbers"
            ValidChars="+-=/*()." />

        <ajaxToolkit:FilteredTextBoxExtender
            ID="FilteredTextBoxExtender4"
            runat="server"
            TargetControlID="TextBox4"
            FilterType="Custom"
            FilterMode="InvalidChars"
            InvalidChars="1234567890" /> --------------------编程问答-------------------- http://www.asp.net/AJAX/AjaxControlToolkit/
官方说明,左边点FilteredTextBoxExtender 就有示例了

补充：.NET技术 ,  ASP.NET