Putting the content (code) for each tab into a different class

Hi,

My application has a few tabs. It's getting hectic having the code for all tabs in a single class. So I decided to move the code for each tab into a separate class.

So now I have a class that represents the main window.

I put the code for each tab into a new class which extends JPanel.

I was hoping that I could add the tabs to the tabbedPane in my main window class like this:

.
.
tabbedPane.add("first tab", new FirstTab());

tabbedPane.add("second tab", new SecondTab());
.
.
(Where FirstTab and SecondTab are the name of the classes that have the code for thaose tabs).

This approach isnt't working; the tabs get displayed but nothing gets displayed onto the tabs.

Any help would be appreciated

Thank you