2010 combobox in formview control

Question

I am trying to determine how to accomplish my requirement in an existing C# 2010 formview control. In 3 separate rows in a formview control, I have 3 different combo boxes that are not functioning right now. The user is suppose to be able to select yes or no from any of the 3  combo boxes. If the user selects yes from any of the 3 different combo boxes, a box is suppose to display so the user can enter a date that needs to be corrected. The place to enter the dates is not suppose to display  until the user selects the yes from the combobox.

Right now the formview control default mode is set to edit so the user can edit the dates right away. Also There is another combo box that updates a database column with yes or no.

I know that I want to use the click event of the yes/no combo box to start the extra entry line(s) to be displayed. However can you tell me how to have these extra lines be displayed?