Show or hide form elements.
setElementHidden( name STRING, hide INTEGER )
Change the visibility of a form element with the setElementHidden() method. You must pass the identifier of the form element. The identifier is the element name as defined in the form definition.
All elements with this name will be affected. If you want to distinguish all form elements, use unique names in the form definition file.
The setElementHidden() method changes the hidden attribute of all form elements identified by the name.
The value passed to hide/show the element can be 0, 1 or 2: