Using combo box in flex

How to use combo box in flex?

<mx:application mx="http://www.adobe.com/2006/mxml"
layout="absolute">
<mx:vbox width="400" height="300">
<mx:panel title="Select Combo Box" paddingtop="50"
paddingbottom="100"
paddingleft="50" paddingright="100">
<mx:combobox id="comBox">
<mx:dataprovider>
<mx:string>AB</mx:string>
<mx:string>CD</mx:string>
<mx:string>EF</mx:string>
<mx:string>Efd</mx:string>
<mx:string>gd</mx:string>
<mx:string>gfd</mx:string>
<mx:string>bjdfgF</mx:string>
</mx:dataprovider>
</mx:combobox>
<mx:textinput id="textInput"
text="{comBox.selectedItem}">
</mx:textinput>
</mx:panel>
</mx:vbox></mx:application>