How do I resend a document?

I found how to require a radio button to be checked.  By right clicking on the radio button, it can be required or changed to a check box.  For people who have been asking what the difference is between a radio button and a checkbox, multiple checkboxes can be checked while only one radio button can be checked. When a radio button is changed to the style of a checkbox, only one checkbox can be checked.

I still don't know how to resend a previously sent document.