iOS Xcode wont download documentation

Hey guys, im trying to jump into iPhone programming this winter break, and i've downloaded the Stanford iPhone class presentations to help me along the way.

I've tried following the assigments, but the require me to self-teach myself stuff through looking at the Xcode documentation (help >documentation)

I have no problem with this aside from that fact that Xcode wont download the documentation. I get a window that looks like this:




Do you guys have any idea how to remedy this?

Thanks.