Set Image as Background

Hi Guys,

I am trying to implement a background image on my webpage but it does not work.

here the code for the css:

.backgroundimage {
               background: url("common/images/blue.jpg");

Here is the implementing code:

 public class LogInView extends VerticalLayout implements View {

        private Navigator navigator;

        TextField txtusername = new TextField("Username: ");
        PasswordField txtpassword = new PasswordField("Password: ");
        Image image = null;
        JDBCConnectionPool connectionPool;

        public LogInView() {

I’m not sure , try not setStyleName() but addStyleName()