Combo-boxes and checkboxes in forms

OK, I’ve worked out the php for the form and need to ask a potentially stupid question before testing. Do I need to treat check boxes and combo boxes any different from regular input text boxes with regards to the code?

At the moment, I have them set up the same. With the checkbox having only two states, do I have to state in the script what those two states are? Also, the combo-box has four different posibilities, with the lack of a var setting in properties, will it work with just the instance name given or am I missing something?

Please forgive the ignorance as I was somewhat thrown in at the deep end with this one.

Thanks in advance.

Stu