How to disable INPUT field in Webdynpro Abap based on some Action.?

I have a Webdynpro screen, where all INPUT fields are displayed in Enabled mode. Based on the user Action condition, some of the INPUT fields needs to be DISABLED (Not Invisible). How to achieve it?

Thanks,

Padma

Edited by: Padmashree RamMaghenthar on Sep 10, 2009 6:29 PM