[flexcoders] Setting combobox selectedindex

[gur_sukh]

The combobox dataprovider sets selectedindex to 0. How do we set it to
something else. 

AS the dataprovider is bound to model and every time it changes the
selected index is 0. 

For demo purposed i need to set this to 1. 

<mx:ComboBox id="productSubTypeCB" width="160"
dataProvider="{selectedProduct.typeNames}"
selectedItem="1"
change="productOffer.productSubType = event.currentTarget.value" />