Transparent picture boxes

Question

I have an application that I allow the user to scroll through a series of jpg images. I have the images in a PictureBox and I want to lay another image on top of it that has a transparent backgroud. I am currently using two picture boxes for this but I can't seem to see the jpg due to the fact that the picture box with the transparent image in it covers it. How can you put a picture box onto of another picture box and be able to see the picture box below it?