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VB

Hello all,
i have the following code thad i write on the dropdownlist databound event
the ID of dropdown list is"dupddatedist"

Protected Sub dupddatedist_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddupdatedist.DataBound
      Dim ddl As DropDownList = DirectCast(sender, DropDownList)
      'add an empty item on top of the list
      AddEmptyItem(ddl)
      Dim frmV As FormView = DirectCast(ddl.NamingContainer, FormView)
      'If frmV.DataItem IsNot Nothing Then

      'Let's pull the province value from the databound item.  The data
      'in my application is supplied by BLL as a dataview.  Therefore each
      'item bound to the FormView is of type DataRowView.  So let's cast
      'that DataItem to the appropriate type to be able to use it
      Dim intDistrict As Int32 = DirectCast(frmV.DataItem, DataRowView)("intContactPerson1DistrictID")
      ddl.ClearSelection()
      'be careful of the possibility that the value saved on the
      'database does not exist in the valid selections that are displayed
      'on the list
      Dim li As ListItem = ddl.Items.FindByValue(intDistrict)
      If li IsNot Nothing Then
          li.Selected = True
      End If

but when i run the code i got following error



Conversion from type 'DBNull' to type 'Integer' is not valid.



please help me out what shoul i do
and also write the correct code for the problem


Thanks and regards
Subiya ahsan