It isn't built-in, but some people recreate the functionality in script:
http://www.eworldui.net/CustomControls/MaskedTextBox.aspx [quoted text, click to view] "Mervin Williams" <mwilliams@innovasolutions.net> wrote in message
news:eQDqy8XLEHA.2100@TK2MSFTNGP10.phx.gbl...
> Does ASP.NET provide the ability to apply edit masks to textbox controls?
> If so, how?
>
> Mervin Williams
>
>