See How to Make Dialogs.
You can use:
JOptionPane.showMessageDialog(frame, "Eggs are not supposed to be green.");
And you can also change the symbol to an error message or an warning. E.g see JOptionPane Features.
See How to Make Dialogs.
You can use:
JOptionPane.showMessageDialog(frame, "Eggs are not supposed to be green.");
And you can also change the symbol to an error message or an warning. E.g see JOptionPane Features.