I have a combo box who's datasource is set to a dataset when the form loads. This combo sets another combo box based on what was selected from the first combo box. I have a clear button, I want to be able to clear the contents of both combo boxes when the button is pressed. I set the datasource of both combo boxes to nothing. Only the second combo box is being cleared. The first combo box is not. Are there any senior level vb.net developers out there that may be able to tell me why this is so. I'd appreciate all the help I can get. Thank you .