Storyline Question on Locking Next Button
I have a course and some of the slides have data entry boxes where I ask the learner to type in a response and then click the next button to move on. I know how to lock the next button for slides without data entry boxes (i.e how to add a variable that says next button only works after timeline ends or after all hotspots are clicked, etc.) but I'm wondering if there is a variable I can add to lock the next button on these slides until the learner has typed responses in the boxes?
I don't want them to just be able to click next and not put anything in the box. Is this possible?