Hi why is it that when i click the view source on any facebook pages, no pages appeared. how do we learn from facebook then? Even friendster doesn't restrict viewing the source.
Some Facebook pages are iframes, make sure you check if an iframe is there. Also Facebook is extremely developer friendly, it has a huge section on development. Dan
IE has a known bug with "View Source", sometimes it is needed to clear the cache. See How to fix the top 10 Internet Explorer issues.
I highly recommend you use Firefox to view the source. The IE view source only seems to work intermittently (as wmtips pointed alluded to).
Facebook development takes place in two different forms: FBML and Iframe. FBML is rendered on Facebook's side, while an Iframe of course loads in an Iframe. Each of these have their own limitations. However it seems most developers in the end turn to Iframe development rather than FBML as the loadtimes are somewhat odd and service can be spotty. However the actual Facebook API is extremely nice to use and is well documented. If you have any questions about the platform please feel free to contact me or ask.