title: Using combobox properties in C# NET 3.5
body: <p>I'd like to know how to set a combobox to be read only,meaning the user cannot write text into it,but just select?</p>
  
  <p>Another question,how to determinate the text of the selected choice.For example it has index of 4 values(10,20,30 and 40).If the user chooce 20,how can I get the Text of the choice he selected(Not the index number,but text)?</p>
  
  <p>Thanks.</p>