How to block alfanumeric entry

["Krzysztof Magrel" <xychu poczta fm>]

I've GtkEntry in my program. I want sometimes allow to entry alfanumeric
signs, and sometimes I wanna entry only digits. How could I do it? I know
how to try what sign is press (event keypressed and event->keyval its the
sign). I thougth, that event->keyval=0 will enough, but not. I still see
every signs ;(  . What szhould I do ?


Krzysztof Magrel
Registered Linux User #157725