How to require text entry

I did something a bit different.  I had 6 text fields that I need content in and so I set it so that I have a trigger for each field, to accept the value when it loses focus. 

I first hid the Next> Button completely.  

Then I added a continue button that would only be active if all the text field values were not blank.  The button forces the last text field to lose focus and then advances the slide.

My participants are taking 6 topics and putting the topics into an order that meets their teams' needs.  So, all I needed was an agenda item (from a prescribed list) in the field.   A drag/drop wouldn't work because those require a correct answer and whatever the participant puts on this slide IS the correct answer for them.

I then have figured out a way to generate an email to my participants with this agenda listed in the order that they typed it.