how to hide buttons on complaint item based on first row selection?

Hi Team,

My requirement is, i have two table view button repair and replacement on complaint item view.if first line item if we select then only this buttons should be visible.this is current scenario.

but our requirement is ,if user select first line item 10 then only return button will be enable,replacement should be hide

                                                        ->after clicking on return button replacement button will come automatically and return button should be hide.

                                                        ->same line item i we click replacement button particular replacement functionality will work.

how to do it.could you please help here.i have added the logic on Do_prepare_output.but it wont work for single line item 3 actions,.

Component - BT120H_CPL

View - BT120H_CPL/ItemList

Method - DO_PREPARE_OUTPUT

Note - when ever if we click return and replacement button EH_ONACTION event should be triggered.

Thanks & Regards

Kalpana