Prerequisites
A valid message class exists in the ABAP program.
Procedure
To add a new message to a message class in the ABAP Editor:
All lines are ready for input.
Note that you cannot create a long text for self-explanatory messages. See also
Creating message long texts.Using forward navigation you can also add a new message to the message class. To do this enter a number for the new message in the MESSAGE statement and double-click it. You are advised to choose the next free number for your new message.
Result
The defined message can be sent to the ABAP program, for example using the MESSAGE statement.