Finding total outward flux?

Here is the question...

Let F=xi-yj+zk and the pyramid be as shown below. Find as a surface integral over all five faces.

http://i90.photobucket.com/albums/k2...18/pyramid.jpg

I really need some help with figuring out the surface integrals of each face. I think that the normal vectors of the two angled faces are and , but I don't understand how to find the dS or the limits of integration since no real equation was given for the surface. I don't know whether I am just not seeing it or what, but can you guys help me out? Thanks in advance.