I create Selector Field but when release not showing readable text

When add value it show the readable key but when release it show the number key. Here is my code.

        [PXSelector(typeof(Search<BAccount.bAccountID, Where<BAccount.status,
            Equal<MegaCustomize.Generics.sT>, Or<BAccount.vStatus, Equal<MegaCustomize.Generics.sT>>>>), typeof(BAccount.acctCD),
            typeof(BAccount.acctName), typeof(BAccount.classID),
            typeof(BAccount.type),
            typeof(BAccount.status), SubstituteKey = typeof(BAccount.acctCD), DescriptionField = typeof(BAccount.acctName))]
        public virtual int? UsrName { get; set; }
    public abstract class usrName : PX.Data.BQL.BqlInt.Field<usrName> { }