Combo Box selected value validating
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/13296801/how-to-validate-combo-box-values-in-c-sharp">How to validate combo box values in c#</a>  </p>
</blockquote>



<p>I have 6 combo boxes in c# form that all fill from database from same column.
i-e for making student result combo boxes fill subject names.
now I want is how to delete Subject name from 2nd combo box if the Subject is already selected in the previous combo box.</p>
