title: Hiding specific items in Combo box temporarily
body: <p>I am a beginner in .NET programming. Trying to do coding with comboboxes. I have two combo boxes with me. The items in both combo-boxes are same. The names of cities. What i am looking for is, when a user selects one city in first combobox, the same city should not be visible in second combo box. I tried 'Remove' and 'RemoveAt' but the problem is, i dont want to change collection or indices of items in the collection. In addition to this, if user selects another city later, the first one should appear again in the list and the later one should get vanished. 
  Please help me on this.. Thank you in advance.</p>