Vista - save image from picturebox

Hi,

I use "visual basic 2005 . I want to scan some fotos into a picturebox. "
Now, i want to store the picture of the picturebox as a file into a specific
map. the filename is written in a textbox.Also i will choose my format (
jpg,pdf, gif, png..)
I've tried with the savefiledialog but with no success.
what kind of code i need to save this picture to eg "D:\test\imageTest.jpg"

if someone knows an ewample of this, let me known.
regards, Rob