I went ahead and made the changes you suggested, and added this line to the form:
<input type="hidden" name="recordID" value="<?php echo($Recordset1->getColumnVal("UserID")); ?>" />
Thank you for the suggestion. I added the following line just below the form:
<button type="submit" form="updateform" value="Submit">Update Records</button>
I am not sure how to add this to the trigger event. Clicking on the lightning does not show an option for the button event.
Thank you very much for your help.