Thanks again for ur meaningful answer Joao,
Your explanation was great.
But my imagination about the handheld device was more than that ! I heard that the handheld guy can create TO to the material document created through a transaction in IM (like MB1B), but according o what you said, he just confirm the TO (he doesn't enter any new data he just check the data which entered before in the TO by scanning the origin, destination and the material bar code), Right?