hi all i have a dropdownlist that bind to a collection of all system colors(ObjectDataProvider).it shows colors name and background of each items is draw with colorName.it works fine . but know i have a listbox that bind to an collection(CollectionViewSource) that shows a list of element with a property name "backcolor" ,i want to selectedvalue of dropdown changed when selecteditem in listBox changed ???? my paltform is WPF and i know a few about masterDetails senario