Cant get the size of my JFrame磗 contentPane, returns 0.

I have a class which extends JFrame. I add a few things to it by using

this.getContentPane().add(someThing);

Right now I need to use absolute positioning so I use the NullLayout

this.getContentPane().setLayout(null);

Therefore I also need to know the sizes of the contentPane. I have tried

this.getContentPane().getSize().getHeight();

this.getContentPane().getHeight();

but both returns 0

[470 byte] By [sandsatera] at [2007-10-3 2:51:25]