I am using vs.net 2003 and the openwave browser emulator 6.2.2.  I have,
what I assume to be a fairly simple problem in that I would like to
constrain a users input to be in the format NN.NN where N is a numeric
digit.  Essentially, I would like to constrain the information to currency.

I have set allowCustomAttributes="True" in web.config and I also set up a
device filter as follows:

<filter name="isUP6x" compare="Type" argument="Openwave 6.x Browser" />

I know that this filter is working, since the following aspx code renders
correctly in the emulator (i.e the this is a up6 browser is shown in the
emulator).

 <mobile:TextBox id="TextBox2" runat="server" Alignment="Left">
 <DeviceSpecific>
  <Choice Filter="isUP6x" Text="this is a up6 browser"></Choice>
  <Choice Text="Default"></Choice>
 </DeviceSpecific>
</mobile:TextBox>

However, when I attempt to add certain attributes "style" or "format" which
are supported by the openwave browser, they appear to be stripped from the
output.  For example:
 <mobile:TextBox id="TextBox2" runat="server" Alignment="Left">
 <DeviceSpecific>
  <Choice Filter="isUP6x" Text="this is a up6 browser"
style="-wap-input-format:NN\.NN"></Choice>
  <Choice Text="Default"></Choice>
 </DeviceSpecific>
</mobile:TextBox>

In this case, the style element is not included in the input.  I have tried
other attributes to see what is going on and certain ones will work.  For
example accesskey="x" will not be stripped out.

How can I get asp.net to include all attributes that I specify in the output
and not only the ones that it sort of pre-approves of?  I can get around
this by custom authoring a control and simply writing out the raw text, but
this seems to be the wrong direction.