Problems

hello sir i am sachin using your online tools, but i have some issues with zoho creator, i have to create a form that gives answer according to the question
i wil give you the example :
there will be 2 Dropdown box "problem code" and " resolution code", problem code will have some option like a, b, c, d, e, f etc... and the resolution code will have some options like 1, 2, 3, 4, 5, 6, etc...., i want to set it up in as way that if i selected problem code as "a" then the resolution should not display all results it should hide some fields and should only show 1, 4 7, 10, etc, and if i selected problem code as "b" then resolution code will change to 5, 11, 14, pls reply soon
sms2luv