im sorry i dont understand! one file has name "main" and the other has "blah". Why is it not possible to program more than one file in one project? thanks
Exactly. This has absolutely nothing to do with the number of files or the file names. If you copy and pasted the content from blah to the other file and only had one file you'd get the same problem as there would be two main functions. Functions are globally scoped so you cannot have the same function name twice regardless of which file it is in.