Hi there, i need to put masks on numerfileds like a phone mask
e.g. (xx) xxxx - xxxx

but i cant find how i can put it


 
<ext:NumberField ID="txtPhone" runat="server" AllowBlank="false" BlankText="Campo obrigatório"
                                                MsgTarget="Side" MaxLength="8" LabelCls="lbl100" FieldLabel="Phone" Cls="txt200">
</ext:NumberField>

Thankss.