SUMMARY
In Microsoft QuickBasic, the FN character combination is reserved for
user-defined functions created with the DEF FN statement. Variable
names, SUBprogram procedure names, and function procedure names
defined with the FUNCTION statement may NOT use FN as the first
characters in the name.
Depending on usage, QuickBasic can give you errors such as the
following when you incorrectly use FN in a name:
Duplicate definition
Invalid identifier
Cannot start with FN
Function not defined
The variable, SUBprogram, or FUNCTION should be renamed so that it
does not start with the FN character combination.
This information applies to Microsoft QuickBasic Versions 2.00, 2.01,
3.00, 4.00, 4.00b, and 4.50, to Microsoft Basic Compiler Versions 6.00
and 6.00b for MS-DOS and MS OS/2, and to Microsoft Basic PDS Version
7.00 for MS-DOS and MS OS/2.
More information on the DEF FN statement can be found in the Microsoft
Basic language reference manual for your version of Basic or
QuickBasic.