Dynamic Search Help on ALV Cells in WEB Dynpro

Hi Experts,

I have created an ALV and displayed with three columns editable (Brand-name, Model-name & Price).

My requirement is!

If i use F4 Help on Brand_name field and then when i use F4 Help on Model_Name field, the Search help should show me only those values which are related to SELECTED BRAND_NAME in the first F4 Help.

EX: 1st F4 Help List (NOKIA, SAMSUNG, MICROMAX, Etc).. If i select NOKIA, then

       2nd F4 Help should Display only NOKIA Model names like (NOKIA LUMIA 520, NOKIA 1600 Etc).. NOT OTHER BRANDS.

Please help me as soon as possible...

Regards:

Azhar