I am using netbeans to develope my gui and it automatically sets up the layout .... but i did not know u could have nested JPanels .... thts gonna help me a lot .... because i need to develope a form which is abt 6 pages long.

though i am developing the gui i am not really understanding why something happen ... i just understand the concept of action listeners and actio performers ... but i really havent yet understood the hierarchy of the swing components ... since this is only my first java application i have to do a lot of trial and error to get wht i want ... am just abt 5 weeks old with java and for tht matter 5 weeks old to OOP.

Thanks

Check out http://java.sun.com, specifically the Swing Tutorial.
Part of the Swing inheritance hiearchy:
Component -> Container -> JComponet -> JPanel
Component -> Container -> Window -> Frame -> JFrame
These two chains are the most prevalent in Swing. The top level stuff like JFrame, JDialog, JApplet and JWindow are like the second chain. Almost all other components are like the first chain (most components descend from JComponent). So when looking in http://java.sun.com/api for JPanel features, be sure to also look at JComponent, Container, Component, etc.
Also, a note on forms: you can attach a JLabel to a JTextField to make them appear grouped together (diffucult to achieve with a layout manager.)