Can't find certain packages

Hello,

I’m a real greenhorn and hope you can help me! Thanks in advance.

Right now Im using the newest vaadin, through eclipse. I reckon Ive downloaded the right stuff and installed it according to guides.

However, some packages seem to not exist. I tried running the source code from here:
http://demo.vaadin.com/sampler-for-vaadin6#DragDropTableTree

However, following packages seem to not be included in my installed Vaadin:
import com.vaadin.ui.Window.Notification;
import com.vaadin.demo.sampler.ExampleUtil;

and hence I cannot run it. What should I change or download in order to get these packages? And where should I put it?

Seems you are using Vaadin 7 but running Vaadin 6 version of Sampler source code.

The Vaadin 7 version of sampler DragDropTableTree can be found at
http://demo.vaadin.com/sampler/#ui/drag-drop/dragdrop-table-tree