identifier expected? What identifier is expected here?

#import "rw.txt" rw

task main()
{
    if(rw != NULL)
    {
        OnRev(OUT_A,75);
        Wait(100);
    }
}

Error: # Error: Identifier expected


I don't seem to be able to find a API describing the NXC API very well..
The error was caused because the file rw.txt was not uploaded to the nxt performing:

 t2n -v -put rw.txt


Solved the problem.