>Hi. I have first name/last name fields. and I only want to allow letters,digits and space there. no special chars. i.e. comma,semicol etc.
>if i use 'N' in inputmask it allows letters and digits but no space.
>can you help me with this? thanks in advance. appreciate.

Mark,
In KeyPress Event of that TextBox you can put:

LPARAMETERS nKeyCode, lShift
LOCAL allowed_chars
allowed_chars = "0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ"
IF NOT UPPER(CHR(nKeyCode)) $ allowed_chars
   NODEFAULT
   RETURN
ENDIF

(not tested)