>>>Wei,
>>>
>>>Check Thread #1061022
>>
>>Hugo, Thank you very much.
>
>You are welcome

Well, I have additional problem with using MouseUp. It doesn't fire when right click on the node. If right clicking outside the node, the fucos (highlight) goes to the node closest to the clicking point while the selected node is kept unchanged. I want to have a right click popup menu for the operation against the selected node. Right mouse clicking will move the highlight off the selected node. How can I solve this problem?