When someone makes a choice from a drop down list, what do you do when they make a mistake. On my form, the selected item doesn't go away.

Hi,

Unfortunately radio buttons assume the user would like one specific selection from that category.  If you would like for them to be able to select and deselect options within the field, I would recommend using a check box.  You could also possible add another option to your radio buttons for "None" or something of that sort as an option if they change their mind.

Let us know if you have any further questions and we will be happy to help.