1. SET HOLD DATA ON.
2. SET HOLD DATA OFF.
The screen attribute 'Allow hold data' is set or reset at runtime. This attribute is normally set dynamically along with the screen. When the 'Hold data' function is set ( System -> User profile) the screen fields changed in the last dialog step are stored. This means that the values are inserted into the fields as proposals if the user returns to the same screen in the same transaction. This only occurs, however, if you have set the 'Allow hold data' attribute. You can control this dynamically using the above statement.