title: Only select list items from combobox
body: <p>I have a winforms application in visual studio 2010.</p>
  
  <p>On a form, I have a databound combobox, for which i have set autocompletesource=listitems and
  autocompletemode=suggestappend.</p>
  
  <p>Now For this functionality to work, I have set dropdownstyle=dropdown, so that user can type a text</p>
  
  <p>But I want a user to be able to select only an item available from its dropdown.</p>
  
  <p>If user enters item other than list items, and leaves combobox, user should not be able to leave combobox.</p>
  
  <p><strong>In short, I want user to be able to select item only from available listitems, not anything he enters.</strong></p>
  
  <p>plz help</p>