I think you're trying to use wrong control. If you provide more details maybe comebody can point you in right direction.

>thanks for your answer
>
>But I can't do that, as I'm trying to develope a some sort of a hierarchical Grid. What I'm really trying to do is to get rid of dynamicinputmask while the user is modifying the field and once the textbox loses the focus establish again
>inputmask.
>
>Help!!!!