VS 2012 Compare 2 listbox ?! Please help me is very important for me.

How to compare two listbox and paint differences (wrong items) ?

listbox1 ______________listbox2_______________listbox2 after press a button

item1________________item1_________________item1
item2________________item2_________________item2
item3________________item4________________ item4
item4________________item4________________ item4
item5________________item6________________ item6 .......