Using Conditions on Triggers for Data Entry

Hey,

The first slide of my course asks the user to type their name into a data entry field. This creates a variable which populates on later pages. The user is instructed to type in their name and then click the "submit" button (a button I placed on the page).  I've hidden the Next button for this page so they can't just continue without typing in their name. BUT, if they click the submit button without typing in their name... I'm going to have the same problem.

I'm trying to figure out how I can put a condition on the "submit" button that says: only take the person to the next page IF they have typed their name into the data entry field.

Does anyone know how to do this?

Thanks!

Mike