I just added my first check box to a datagridview. On the screen there is a date prompt and a Display button. The user can change the date and then hit the display button and the dgv refreshes. The problem I have is which each click of the Display button the dgv shows one more check box. So the screen starts out with one, then two, three and so on. HOw do I correct this code so there will always only be one checkbox column?