Volume of the Cap of a Sphere

Well I figured out the volume of a Torus alright (deleted?), but now I'm strugglin' with this next problem

Basically I have to use integration techniques for find the formula for the volume of the cap of a sphere with a radius R and the cap having a height h.

Here's what I have (i feel like MacGyver saying that) so far:

I don't think I had an problems setting up the integral correctly... however once I solve for it, pi simply cancels out (but is needed in the final formula). I know R is a constant as well as h, however, I’m a little hesitant to drag out the R^2 to the front leaving the -x^2 to be integrated. Any help would be greatly appreciated.

I tried using math tags, however I couldn't get the integrals set up right with limits, so figured a scan of my work would be alright. Hope its readable :o

http://img151.imageshack.us/img151/3...eone7jj.th.jpg

http://img151.imageshack.us/img151/4...etwo2nw.th.jpg

If I'm doing this the long why, by all means let me know