Visual Basic

Public Function adminlevel() As Dataset<br />
        Dim adminsql As String = "Select * from userlevel"<br />
        Dim admindata As New SqlClient.SqlDataAdapter(adminsql, con)<br />
        Dim adminset As New DataSet<br />
        con.Open()<br />
        If con.State = ConnectionState.Open Then<br />
            admindata.Fill(adminset, "userlevel")<br />
           <br />
                admlevel = adminset.Tables("userlevel")<br />
           <br />
                  con.Close()<br />
            'Catch ex As Exception<br />
            '    MsgBox(ex.Message)<br />
            'End Try<br />
        Else<br />
            MsgBox("No Connection")<br />
        End If<br />
        Return admintable<br />
    End Function<br />
<br />
<br />
//at form end I have following code to bind combo box cboUser to a databse field.Stepping thru the code  line cbouser.displaymember="levelname" returned the error after the code.<br />
<br />
 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load<br />
        Try<br />
            Dim myuserlevel As New Underwriter.Underwriter<br />
            Dim load As New DataTable<br />
            load = myuserlevel.adminlevel()<br />
            cboUser.DataSource = load<br />
            cboUser.DisplayMember() = "levelName"<br />
            cboUser.ValueMember() = "levelname"<br />
        Catch ex As Exception<br />
            MsgBox(ex.Message)<br />
        End Try<br />
<br />
    End Sub<br />
<br />
the error returned is below:<br />
Could not bind to the new display member <br />
Parameter: newDisplayMember

'---------------- Test.vb ------------------------------------------------------
Imports SHDocVw

Module Test

    Public Class clsTest
        Public HWND As Long
        '
        ' Omitted additional members goes here.
        '
    End Class

    Public Sub doSomething(ByRef c() As clsTest)
        Dim i As Integer
        Dim ieCollection() As InternetExplorer = Nothing

        '
        ' Omitted code that populates ieCollection goes here.
        '

        i = 0
        For Each ie As InternetExplorer In ieCollection

            ' [Insert #1]

            c(i).HWND = ie.HWND

            i += 1
        Next
    End Sub

End Module
'---------------- End of Test.vb -----------------------------------------------


'---------------- Main.vb ------------------------------------------------------
Module Main
    Private Class clsTestExtended
        Inherits Test.clsTest

        Public strParam1 As String
        Public strParam2 As String
    End Class

    Public Sub main()
        Dim ce() As clsTestExtended = Nothing ' [Change #1]

        ' [Insert #2]

        Test.doSomething(ce)

        For Each c As clsTestExtended In ce
            c.strParam1 = ""
            c.strParam2 = ""
        Next

    End Sub
End Module
'---------------- End of Main.vb -----------------------------------------------

If c Is Nothing Then
	ReDim c(0)
Else
	ReDim Preserve c(i)
End If
c(i) = New clsTest

Unable to cast object of type 'clsTest[]' to type 'clsTestExtended[]'

Dim ce(1) As clsTestExtended

ce(0) = New clsTestExtended
ce(1) = New clsTestExtended