ok , points noted Mr. stanav. i tested your solution without any sucess, the problem is that the user creates two post back events before even the server disables the comboboxes in the first postback.

and i agree if any one here can move this post to asp.net i will be thankul, but please note that i posted this post here because i only use vb.net code inside the web project i am using.

thx (-: