GWT - How to add an easy ComboBox

I need the GWT Class that describes an easy ComboBox. Looks strange, but i can't use it. I found this but if i try ComboBox combo=new ComboBox(); i can't import the package (there is no way to import it on NetBeans). The same for ComboBoxItem cbItem = new ComboBoxItem(); (but this should be for Smart GWT Library).

These are the actual import :

import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.FlowPanel;
import com.g开发者_开发问答oogle.gwt.user.client.ui.InlineLabel;
import com.google.gwt.user.client.ui.TextArea;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.Widget;

Maybe some conflicts? I ask sorry, i think this is a stupid question :)

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The link you point if from the GXT framework, so you need to import the proper library.

What you're looking for is probably the ListBox widget: see the examples here