DataSource Controls :: How To Pass Null Value Into Varbinary(max) Column N To By Table

i want to pass null value into varbinary(max) column n to by table

if i do like this i have this function in my app_code .vb class

Public Function Remove_Attachment(ByVal Id As Integer) As Integer
Try
Dim db As New dbAccess
db.commandText = "SP_RemoveAtt_DML"
db.commandType = CommandType.StoredProcedure
db.addParameter("@InOutVal_Id", Id)
db.addParameter("@Document", System.Data.SqlTypes.SqlBinary.Null.Value)
db.executeQuery()
Catch ex As Exception
Throw ex
End Try
End Function

i got this error. Data is Null. This method or property cannot be called on Null values.