editing XML files in netbeans, which use XML Schema description

During the development I have to edit XML files, which are based on an xml schema description

There is a code like :

To get Code-Completion in Netbeans you have to add the reference to the
correct schema.

In the IDE-Menu go to Tools->DTDs and XML Schemas.
In the window go to "User Catalog" and press "Add Local DTD or Schema"

Now in the System-ID enter "http://xxx.xxx/a/b/" and for the
URI field select the xsd-Schema file.

After this you can hit the Code-Completion-Shortcut and
you get help.