Java Development Tools

I have two questions:

1. I'm trying to automatically expand the first level tree nodes upon display of the tree. I tried to initialize a RowKeySetImpl object, and added ArrayList of first level nodes, and used setDisclosedRowKeys method. The tree nodes are not rendered properly. If I take the following code out, then the tree content is rendered properly. Here is my code. I have three nodes that I want to expand.

ArrayList node1 = new ArrayList();
node1.add(new Integer(0));

ArrayList node2 = new ArrayList();
node2.add(new Integer(1));

ArrayList node3 = new ArrayList();
node3.add(new Integer(2));

RowKeySetImpl expand = new RowKeySetImpl();
expand.add(node1);
expand.add(node2);
expand.add(node3);
this.mainTree.setDisclosedRowKeys(expand);

2. I have a Panel Splitter, on the first facet, it contains a tree, on the second facet it will be either 'task list', or 'edit task'. When user selects a task in the 'task list', I would like to display 'edit task', while highlight the selected 'task' node on the tree.

In respond to the ActionListener of the command link (each command link corresponds to task):
1. How do I determine the properly node in the tree?
2. I constructed a RowKeySetImpl object and called setSelectedRowKeys. But I get messagebox saying "To display the webpage again, Internet Explorer needs to resend the information you've previously submitted." If I clicked Retry button, the message box just gets displayed again. If I cancel, the node I hardcoded does get selected properly.

Please help me!

Thanks,