Add a new empty row in bind combo

Hi; I have a ComboBox (VS 2003) linked to DataSet; but I need add a new empty row (on the top) for select nothing.

How can I make this?

Thanks

OK, I found the answer. It's this (if someone is insteresting):

Private Sub FillComboAgentes()
Dim list As New DataTable
Dim DRow As DataRow
Dim X As Int16 = 1

list.Columns.Add(New DataColumn("Nombre", GetType(String)))
list.Columns.Add(New DataColumn("AgenteID", GetType(Integer)))
list.Rows.Add(list.NewRow())
list.Rows(0)(0) = "--- Ninguno ---" '
list.Rows(0)(1) = DBNull.Value

For Each DRow In TargeDS.Agentes
list.Rows.Add(list.NewRow())
list.Rows(X)(0) = DRow("Nombre") & " " & DRow("Apellidos")
list.Rows(X)(1) = DRow("AgenteID")
X += 1
Next

C_Agentes.DataSource = list
C_Agentes.DisplayMember = "Nombre"
C_Agentes.ValueMember = "AgenteID"
End Sub