it just gives the dialog box a parent nothing much to it. It also provides the Co-ords that the dialog box uses. You do not need to specify a parent frame as you can just set it equal to null. This will then use a default frame and the dialog box will be centred
String choose= JOptionPane.showInputDialog(null, menu + Option1 + Option2+ Option3+ Option4+Option5);
Should work fine for you.
This page covers these things,
Java Doc - JOptionPane.showInputDialog
Chris