Using vb.net 2005 with Crystal Reports.

I have a crystal report with FieldObjects (technically "iFieldObjects") on the report from a typed Dataset.  In the report I am showing Address fields for customers using 3 fieldObjects:

FieldObject_Addr1: Address1

FieldObject_Addr2: Address2

FieldObject_Concat_City_State_Zip:  City, State Zip

In the vb.net code there are certain situations (ex:  "Address2" value is null) when I want to hide the FieldObject and I would like to set the height of the fieldObject_Addr2 to nothing so that there is no blank line between Address1 and the City_State_Zip values.

The main idea is that I want to programmatically, either in vb.net or in a formula on the report, change the height/width of a FieldObject at runtime. 

How to do this?  I tried this below but it's not working

Dim fldObjAddrLine2 As CrystalDecisions.CrystalReports.Engine.FieldObject


If myDataSet.Tables(0).Rows(i).Item("Address2") = "" Then
    fldObjBillAddrLine2 = CType(crRpt.ReportDefinition.ReportObjects.Item("AddrLine2"), CrystalDecisions.CrystalReports.Engine.FieldObject)


    fldObjAddrLine2.Width() = 0
    fldObjAddrLine2.Height() = 0
End If