This error message means that you specified an argument to a command that is outside it's valid range. This most often happens with commands like Output( and Text(. You would get this error message using these commands if you put a number outside their range for rows or columns. An example would be: Output(10,23,"B"). If you know anything about programming you'll know that the greatest number for rows in Output( is 8 and the greatest number for columns is 16. That command line above, wasn't in either range. If you were to put that in a program and run it, you would get an "ERR:DOMAIN" error message. If you're not asbolutely sure what the valid range for a command is, go to the Index of Commands and click on the command. The valid range will be listed somewhere in the paragraph.