Vaadin+GAE

Hi:

Is there a step by step guide to create a vaadin project in Google App Engine?..What are the requirements?

thanks!!

I´m following the instructions at
https://vaadin.com/wiki/-/wiki/Main/Google%20AppEngine%20HOWTO
and when I try to deploy the app to GAE I get this error:

I have an error in the project but it doesn´t show where…I guess that the dialog that appears whenI try to deploy has to do with it…

any ideas…