Hi Frank,
Thanks very much that's put my mind at ease, didn't like to think that I was not able to do something that simple. At least it was something easy to sort!
Having a look through they seem to be the only thing that Nasm is case-sensitive with. Very strange!
As for the Ide that I am using, it is Robert Andersons NASM-IDE 1.8 , it is just what we were asked to use by my University, so as a beginner I have stuck with it.
I have to build up a portfolio of code in the next few weeks so if stuck I may call upon you again if this is ok?
Thanks,
Ben