Custom system message vaadin portlet in liferay portal

Hi,
I can't custom system message vaadin portlet in liferay portal. I use vaadin 7.5 and liferay 6.2.
Please help me, Thank you!

Not sure what you're asking for here.  You want to customize the look of the messages or customize the messages themselves?

Sorry, My english is bad. I want to customize content of message "Communication problem take note of any unsaved data, and click here or press Esc to continue." in Liferay vaadin portlet.

That is rendered by the javascript.  It's either going to be part of the Vaadin core or the compiled widgetset.