Write a simple Java application which will convert a base 10 integer numeral to another base.
The application should show a text field with a label, a JSpinner, an uneditable text field, and a button.
The labeled text field is for input, and the uneditable text field is for the output.
Values on the spinner should vary from 2 to 20.
The button should be labeled "Exit" and when clicked should cause the program to terminate.
The user can enter the base 10 numeral in the labeled text field.
A corresponding numeral should appear in the output text field in the base selected on the spinner.
If the input is not a valid base 10 numeral, the output field should indicate an error.
The output field should update with each change to the input field, and also with any change to the
spinner.
The background of the JFrame should be some color other than the default color.
Set the size of the window to 1/3 of the size of the user's screen, and center the window on the screen.
The program should terminate when the user closes the window or clicks the exit JButton.