CRM Web UI - how to disable REJECT and END in IC header

Hi All..

Requirement is to disable REJECT and END buttons in Interaction center role based on some conditions for a Z-Transaction type.

Scenario:

User selects “Service Concern”.

Does not selects Save or Cancel.

Directly going to REJECT or END.

So trying to put restriction on both the buttons. How to achieve this??

thanks in advance.