You are attempting to create a new element in your program
and have given it a name that is already being used.
Examples of this are:
  - Giving a new procedure the name of an existing
    procedure.
  - Giving a new variable the name of an existing
    procedure.
  - Starting a variable name with the letters FN.
 
There can also be a conflict of file names. Attempting to
create a file using the name of a file that already exists
in the current directory will cause this error.
 
Either
  - Use a different name in the dialog box, or
  - Cancel the command and either change the name of the
    existing item that is causing the name conflict, or
    delete it.