1. A method for creating a computer programming library file containing at least one subroutine for performing a function, the function being used in a non-script programming language or the function being run as a script in a script programming language, comprising the steps of: creating a library file having a predetermined given name in a predetermined program file; creating at least one subroutine having a name identical to said predetermined name of said library file; creating code configured to test the operability of said created at least one subroutine, said code being placed in said library file and being executable only when a name of said predetermined program file matches said name of said created at least one subroutine.