Events in Reports

Classical Reports generates the Basic List and Interactive reports generates the Up to 20 Secondary Lists.
Sequence of events -
INTIALIZATION
AT SELECTION-SCREEN OUTPUT
AT SELECTION-SCREEN ON
AT SELECTION-SCREEN
START-OF-SELECTION
END-OF-SELECTION
TOP-OF-PAGE
END-OF-PAGE
AT USER-COMMAND
AT PF()
AT LINE-SELECTION
Initialization: is the event to get assign the value as a default(nothing but the initialization of the variable). It is the first event to trigger but if your program contains parameters or Select Options it trigger but not show the output on the list.
AT SELECTION-SCREEN OUTPUT -PBO for selection screen, just before displaying the screen
AT SELECTION-SCREEN ON - PAI on field
AT SELECTION-SCREEN - PAI of the selection screen
Top-of-page: is the event to design the header of the list. It is the only the event trigger after the initialization. Fist the control goes to Start-of-selection and then system(driver program ) searches for the Top-of-page envent if it has declared, immediatly control goes to that event and print the data whatever you given under that event.
Start-of-Selection: is the event to picking up the data from the database and for generating the Basic list data. It triggers after the top-of-page event. By defualt system declares this event, if you forget to declare in your report.

End-of-Selection: is the event that let to know the system program has just completed the execution of the Start-of-Selection event. it triggers after the Start-of-selection event.

End-of-page: is the event to display the Total Calculations or Page No.s and Footer Headings.

At PF: is the event to generate the GUIs(Graphical User Interface) like tool bars, application bar, title bar, Menu bar etc.,

At User-Command: used for generates the Push Buttons , Command Buttons etc., These events will trigger when the user perform some actions like pressing the command button .

At Line-Selection: is the event to geneartes the Secondary Lists, it will trigger when the user double click or press F2 key on the list contents. for generating the Secondary list sap provided predifined statements: SY-LIST,SY-LILLY,etc.,for entire record ,if you double click anywhere on the record it generates same secondary list. if you want to generate the secondary list based on the field you can go for GET CURSOR FIELD fieldname VALUE fieldvalue.

Top-of-page During Line-Selection: is the event to generate the Headers during on the Secondary List. You can generate different page headers for secondary lists