Allow only digits 1 - 3 in TextBox control in ASP.Net

Hi Rohit do the following way

<div>
        <Ajax:ToolkitScriptManager runat="server"></Ajax:ToolkitScriptManager>
        <asp:TextBox ID="txtItemCount" runat="server" MaxLength="1"/>
        <Ajax:FilteredTextBoxExtender ID="ftItemCount" runat="server" ValidChars="123" TargetControlID="txtItemCount" FilterType="Custom"></Ajax:FilteredTextBoxExtender>
    </div>

Thanks and Regards,

Rk_Hirpara