Multi Button class

Hi all, my challenge is to create a custom button that as folder like behaviour example:
-componentName, with a queue Link (Link [])
-action_1(Link [0])
-....
-action_n[Link[n-1])
the goal is when the component was instanciated, two args will be passed:
-componentName;
-String[] with the name of each subComponent(Link.caption);
The
I've created such a class, but when it is called to render, a null exception is thrown... i'll had the code as soon as i can.
Anyone knows why this is happening?
Pedro

Impossible to know without some code unfortunately. The stack trace would help too.