ListBox Problum

hello guys.i am working on listboxes. i have two listboxes.first listbox i have department names. second listbox. i have names .
 if i select first listbox on one department the second listbox related data should come.i have the below error in screen action.

Invalid Data Type

The same 'Record' data type required. Expected 'ListBox' instead of 'Boolean, ListBox'.

please help me .