> For example I have to add "using namespace std;" to use cout, cin etc.
Does your BC++ compiler not accept this or something? If it doesn't, then consider getting a better compiler which does.

Besides, using namespace std; is poor style as you get EVERYTHING in the standard namespace, not just the things you need (it's a bit like using globals - sure it works, but it ain't pretty).
Use things like
std::cout << "hello world" << std::endl;


> What do I have to add to make it work on Dev?
Depends on what you mean.
Does it compile?
Does it run?
Does it produce the same results?

> i<=1;
Erm, what's this supposed to do?
Compare i (which is uninitialised) with 1, and throw the result of the comparison away.
Try i = 1;
if you want consistency.

> At home I use Dev C++ which is a little different from BC++
Being able to write code which works on any compiler should be the aim of every programmer.

It's a lot harder to do that than just figuring out what your current compiler will let you get away with, but it will serve you well in the long run.