How to take into account different screen sizes?

I have written a JAV开发者_运维知识库A desktop application using Netbeans IDE, when I run the application it looks perfect on my laptop. However when I installed it on a larger screen laptop, there is some extra space. What is the best way to get rid of that? Is there a way I can support multiple screen sizes in my source code or should I create a copy of the project and install netbeans and do the resize at the new computer which defeats the whole purpose?!

thanks

If you are using Swing, you can use any of the different layout managers. http://download.oracle.com/javase/tutorial/uiswing/layout/using.html