// creating the Menu and registering it
		MenuManager menuMgr = new MenuManager("#PopupMenu");
		menuMgr.setRemoveAllWhenShown(false);
		Menu menu = menuMgr.createContextMenu(treeViewer.getControl());
		viewer.getControl().setMenu(menu);
		getSite().registerContextMenu(menuMgr, treeViewer);

		Action action1 = new Action() { 
			public void run() {
			// Code for handling action goes here. 
			}
		} ; 
		action1.setText("Action 1");