extra face.

When I try to make a certain shape with a block, and extra face appears for some reason. The face is made with only edges for some reason. If anyone can help on how to get rid of this it would be a lot help.

http://img322.imageshack.us/img322/3060/capturewiz002sk0.jpg

http://img322.imageshack.us/img322/1388/capturewiz003pa0.jpg

you have two faces on the bottom then one over top. select the 4 verts, press delete and choose faces. select them all again and press f. this will connect them with 1 face and get rid of those edges.

a really nice illusion trick !