Added dynamic text; How do I stop variable name from showing?

I am creating a simple game for kids.  On the first page, I added an "input text" field for their first name.  I called the variable firstname.

When they move to the next page, I used a "dyanamic text" field so I can call them by name on this page.  It works.  However, When I test the game, on the first page, where the firstname is input, it shows    _level0.firstname          instead of just a blank space for them to input their name.

I know I fixed this in the past and it was something simple, but I can't remember how to do it.  I'd appreciate anyone's help!

Thanks.