Does that actually compile? I think I can see at least three errors there?
#include <iostream.h> should be #include <iostream> (uses the newer library)
missing using namespace std or should have std:: at the beginning of cin and cout
main should have a return type of int.
No, that should work - the C++ headers with .h on the end are basically the non-namespaced versions (I think they're mainly a hangover from when C++ was still evolving, but IIRC, they are part of the standard).
As for the no return type on main(), I know Visual C lets you do that, but I'm not sure whether it is 'correct' or not