Combining images with transparency

Hi. I have two pictureboxes. One contains a pattern, one contains an arrow-shaped graphic on a white background. I want to copy the arrow onto the pattern, but remove the white background.

Basically I want to superimpose the arrow (without the white) onto the pattern. How would I do this?

UPDATE:
I've already tried loading a GIF with transparency of the arrow into the 2nd picturebox. Instead of white, the color surrounding the arrow is gray when I copy it

Use the Image control with the GIF, not the Picturebox control ;)

I have other idea... If you want to hear it just tell me, it seems they solved your problem already.