Set selected Production order's Order type in another field

Hi all,

I have a selector in SOLine grid as follows.

#region UsrProductionNbr
        [PXDBString(15)]
        [PXUIField(DisplayName = "Production Nbr")]
        [PXSelector(
            typeof(Search<AMProdItem.prodOrdID,
        Where<AMProdItem.inventoryID, Equal<Current<SOLine.inventoryID>>>>),
          typeof(AMProdItem.orderType),
            typeof(AMProdItem.prodOrdID))]
        public virtual string UsrProductionNbr { get; set; }
        public abstract class usrProductionNbr : PX.Data.BQL.BqlString.Field<usrProductionNbr> { }
#endregion

I have another field for production order type in the same grid as follows.
 

        #region UsrProdOrdType
        [PXDBString(5)]
        [PXUIField(DisplayName = "Prod. Order Type", Enabled = false)]
        public virtual string UsrProdOrdType { get; set; }
        public abstract class usrProdOrdType : PX.Data.BQL.BqlString.Field<usrProdOrdType> { }
        #endregion

I want to set the UsrProdOrdType value based on selected production order in UsrProductionNbr selector once it is selected. 

How can I do this?

Thanks.