With the help of Ajax Filtered TextBox Extender, we can filter the value entered in the textbox
The Following Example will allow only numbers to be typed in the textbox also we can specify the range of the numbers or the alphabets they showed be typed or not
We can filter it as we can specify wheather to allow number only,characters only, special symbols only or combination of 2 or more
How To Use:
<form id="form1" runat="server">
<asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
</asp:ToolkitScriptManager>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:FilteredTextBoxExtender TargetControlID="TextBox1" FilterInterval="0"
FilterMode="InvalidChars" FilterType="Numbers"
ID="FilteredTextBoxExtender1" runat="server" ValidChars="789">
</asp:FilteredTextBoxExtender>
</form>