>Thanks for the that.
>
>The problem however is that I still want to restrict the user from
>input of a large InputMask.
>
>The example
>
>Field One, if used, is restricted to an input of 9999.99
>Field Two, if used, is restricted to an input of 99999.99.
>The user can input into only one of the two fields.
>
>If Field One is chosen, the Field Two will autofilled to a possible
>999999.99 max. However, if the user changes his/her mind, and/or edits
>and wants to use Field Two, it must only have a InputMask of 99999.99, (i.e one less digit)
>
>Whilst long drawn out code within each field could be achieved, it a long task.
>Especially as I have five fields within the same input function.
>?

If this is the case, you should do it programmatically, in texbox GotFocus/LostFocus events. Also note, that you can use MaxLength instead of InputMask (AFAIK). As I said, the code would be a little tricky.

Try to set your InputMask in a form's code and if you still would not achieve your result, show some your code, please, we'll try to help.