The ConnectionString not initialized

The ConnectionString not initialized

Good day All i have an issue with connection string I' m having this error
"The ConnectionString property has not been initialized." on the
RowDataBound of the outer gridview sub routine (VB.NET)
when trying to bind data to inner gridview
the code:
Private Function ChildDataSource(ByVal strCustometId As String, ByVal
strSort As String) As SqlDataSource Dim strQRY As String = ""
Dim connString As String =
ConfigurationManager.ConnectionStrings("SiteConnectionString").ConnectionString
Using conn As New SqlConnection(connString)
conn.Open()
strQRY = "SELECT [Sortie].[OdvID],[Sortie].[SortieID]," &
"[Sortie].[Fuel],[Sortie].[Captain],[Sortie].[Crew] FROM [Sortie]"
& " WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "UNION ALL
" & "SELECT '" & strCustometId & "','','','','' FROM [Sortie]
WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "HAVING
COUNT(*)=0 " & strSort
'Initialize command object
Dim cmd As New SqlCommand(strQRY, conn)
Dim dsTemp As New SqlDataSource()
dsTemp.SelectCommand = strQRY
Return dsTemp
End Using
End Function
'This event occurs for each row
Protected Sub gvOdv_RowDataBound(ByVal sender As Object, ByVal e As
GridViewRowEventArgs)
Dim connString As String =
ConfigurationManager.ConnectionStrings("MoyensAeriensConnectionString").ConnectionString
Dim conn As New SqlConnection(connString)
conn.Open()
Dim row As GridViewRow = e.Row
Dim strSort As String = String.Empty
' Make sure we aren't in header/footer rows
If row.DataItem Is Nothing Then
Return
End If
'Find Child GridView control
Dim gv As New GridView()
gv = DirectCast(row.FindControl("gvSorties"), GridView)
'Check if any additional conditions (Paging, Sorting, Editing, etc) to
be applied on child GridView
If gv.UniqueID = gvUniqueID Then
gv.PageIndex = gvNewPageIndex
gv.EditIndex = gvEditIndex
'Check if Sorting used
If gvSortExpr <> String.Empty Then
GetSortDirection()
strSort = " ORDER BY " & String.Format("{0} {1}", gvSortExpr,
gvSortDir)
End If
'Expand the Child grid
ClientScript.RegisterStartupScript([GetType](), "Expand", "<SCRIPT
LANGUAGE='javascript'>expandcollapse('div" &
DirectCast(e.Row.DataItem, DataRowView)("OdvID").ToString() &
"','one');</script>")
End If
'Prepare the query for Child GridView by passing the Odv ID of the
parent row
gv.DataSource = ChildDataSource(DirectCast(e.Row.DataItem,
DataRowView)("OdvID").ToString(), strSort)
gv.DataBind()
'Add delete confirmation message for Customer
Dim l As LinkButton = DirectCast(e.Row.FindControl("linkDeleteCust"),
LinkButton)
l.Attributes.Add("onclick", "javascript:return " & "confirm('Are you
sure you want to delete this Customer " &
DataBinder.Eval(e.Row.DataItem, "OdvID") & "')")
End Sub
thanks (I'v been hunting this error for last 3 hours)