HI mindstick!
How to disable drop down list box by clicking check box in gridview (ASP)
Ask by Anonymous User
Updated 17 Jul 2013
When I wanted to show/hide something I used nameWantToHide.setvisible technically this should also work for you. So On your check box a statement saying if checked droplist.setvisible=0 ( I can't remember the exact code without having an IDE to work with but this gives an idea if what you could do ).