All GALIB functions return an error code.  Zero means that there were no errors during the call of a function; a non-zero code means that an error occurred.  The module GALIB32.BAS contains a special function called GA_error, that returns a text string.  This function has the following specification in Visual Basic:

              Function GA_error$ (errorcode%)

This function returns a string containing a short description of the error for the code which was passed to it as an actual parameter.  Use this function to create your own error handling subroutine.  It is similar to the Visual Basic Error$ function.

Complete description of error codes and error messages returned by the GA_error function can be found here.