It is important that you understand what a modal dialog is.

Currently the MainMenu is starting the ProductEditor in modal mode. Test this by running the Main class clicking the <

Let's make the dialog non-modal. Open the button click handler in the MainMenu frame. In the line of code that creates the ProductEditor dialog instance change the boolean parameter to false. Test the system again. Can you open multiple ProductEditor dialogs now?

This is quite dangerous since we now have to worry about bugs that can be created by having multiple instances of the dialogs being used by the user concurrently. For example, what would happen if the user managed to edit a product and then delete the same product from a different dialog before saving the edited product? Nothing good.

Change the parameter back to true again since we want the dialog to be modal.