Update internal table

Hi,

ITAB

EBELN PLANT TEXT

12 ABC SD

12 ABC MM

12 ABC AS

13 SRT AD

14 DFG RT

15 DFG SD

JTAB

EBELN PLANT

12 SDF

13 ABC

14 ABD

15 BWR

On the basis of JTAB ITAB should be modified and it should look like

ITAB

EBELN PLANT TEXT

12 SDF SD

12 SDF MM

12 SDF AS

13 ABC AD

14 ABD RT

15 BWR SD

How is this possible.