V.V. easy vb code debugging (about DDRAW)

I post the message in the feedback sections as anyone would help me in dubugging a VB code, even if it is very very simple.
It's about direct draw blitting function; I just cannot show a bitmap on the primary surface, but any error code is given.
Please, help me if you can,

NEMINIS

This should either be in General VB or Games and Graphics :)