[ABAP] SET SCREEN/CALL SCREEN/LEAVE TO SCREEN

With SET SCREEN the current screen simply specifies the next screen in the chain , control branches to this next screen as sonn as th e current screen has been processed .Return from next screen to current screen is not automatic .It does not interrupt processing of the current screen.If we want to branch to the next screen without finishing the current one ,use LEAVE SCREEN.
- With CALL SCREEN , the current (calling) chain is suspended , and a next screen (screen chain) is called .The called can then return to the suspended chain with the statement LEAVE SCREEN TO SCREEN 0 .Sometime we might want to let an user call a pop up screen from the main application screen to let him enter secondary information.After they have completed their enteries, the users should be able to close the popup and return directly to the place where they left off in the main screen.Here comes CALL SCREEN into picture .This statement lets us insert such a sequence intp the current one.
If we use SET SCREEN without LEAVE SCREEN, the program finishes processing for the current screen before branching to <scr no>. If we use LEAVE SCREEN without a SET SCREEN before it, the current screen process will be terminated and branch directly to the screen specified as the default next-screen in the screen attributes.
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LEAVE TO SCREEN 0 or (SET SCREEN 0 and LEAVE SCREEN) .When u return to the suspended chain execution resumes with the statement directly following the original CALL SCREEN statement.The original sequence of screens in a transaction (that is , without having stacked any additional call modes),you returned from the transaction altogether.
LEAVE TO SCREEN 0 or (SET SCREEN 0 and LEAVE SCREEN) .When u return to the suspended chain execution resumes with the statement directly following the original CALL SCREEN statement.The original sequence of screens in a transaction (that is , without having stacked any additional call modes),you returned from the transaction altogether


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