state and city in the same dropdown

Dictionary<string,>> dictionary = new Dictionary<String, List<String>>();
//Add items to the dictionary
dictionary.Add("Statename1", new List<string>(new [] {"city1", "city2"}));

//Iterate over the dictionary
foreach(var pair in dictionary)
{
    //Add statename
    dropdownlist.Items.Add(pair.Key);
    foreach(var city in pair.Value)
    {
        //Add cityname
        dropdownlist.Items.Add(city);
    }
}
</string>

<pre lang="vb">Partial Class _Default
  Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        BindDropdown()
    End Sub

    Protected Sub BindDropdown()
        'by manually adding the listitems, we can easily alter them as they are added
        For Each dataItem As TestData In TestData.GetTestData
            Dim li As New ListItem
            li.Value = dataItem.Value.ToString
            'we can easily combine multpile properties from our "datasource" to get a display value
            li.Text = dataItem.Prop1 & " " & dataItem.Prop2
            Me.DropDownList1.Items.Add(li)
        Next
    End Sub

End Class

'this Class is just something to give us some test data for our example
Public Class TestData
  Public Shared Function GetTestData() As ArrayList
    Dim result As New ArrayList
    For x As Integer = 1 To 25
      result.Add(New TestData)
    Next
    Return result
    End Function
    Public ReadOnly Property Value() As Integer
        Get
            Return 1
        End Get
    End Property
    Public ReadOnly Property Prop1() As String
        Get
            Return "Value1"
        End Get
    End Property
    Public ReadOnly Property Prop2() As String
        Get
            Return "Value2"
        End Get
    End Property
End Class