You want to keep subsidiary form controls hidden until they are needed in response to other control settings.

You can keep more detailed controls hidden from view until a user chooses an item in a select element or turns on a checkbox using a function that is similar to the togglePurDec( ) function shown in the Discussion to hide and show a relevant group of form controls.

An alternative to disabling form controls (Recipe 8.9) is to hide subsidiary groups of controls until they are needed. For example, the following excerpt from a magazine subscription form has nested controls that remain hidden until the user answers Yes to question number 3: