Step 1,2,3 & Validation check + message class

The enhancement RSR00001 (BW: Enhancements for Global Variables in Reporting) is called up several times during execution of the report. Here, the parameter I_STEP specifies when the enhancement is called.

I_STEP = 1
Call takes place directly before variable entry. Can be used to pre populate selection variables

I_STEP = 2
Call takes place directly after variable entry. This step is only started up when the same variable is not input ready and could not be filled at I_STEP=1.

I_STEP = 3 In this call, you can check the values of the variables. Triggering an exception (RAISE) causes the variable screen to appear once more. Afterwards, I_STEP=2 is also called again.

I_STEP = 0
The enhancement is not called from the variable screen. The call can come from the authorization check or from the Monitor. This is where you want to put the mod for populating the authorization object.

Full text available here.