I have a problem while maven packaging. In this code:

```
public class LoginDialog extends Dialog {

    private final TextField<String> customer;
                          ^here
    private final TextField<String> login1;
    private final TextField<String> password1;
    private final MainController controller= new MainController();
    private String customerId;
    private String login;
    private String password;

```

I have an error like:

```
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure
...src/main/java/com/messagedna/web/client/widget/LoginDialog.java:[19,27] error: generics are not supported in -source 1.3

```

what may be the reason of this?