Reverse DropDownList Items on Button click in ASP.Net

HTML

<div>
        <asp:DropDownList ID="myDropdownlist" runat="server">
            <asp:ListItem Text="Aura" Value="Aura" />
            <asp:ListItem Text="Adrani" Value="Adrani" />
            <asp:ListItem Text="Celsi M." Value="Celsi M."/>
            <asp:ListItem Text="Karilo" Value="Karilo" />
        </asp:DropDownList>
        <asp:Button Text="Reverse DropdownList" runat="server" OnClick="OnReverse" />
    </div>

CODE

protected void OnReverse(object sender, EventArgs e)
    {
        List<ListItem> listItems = new List<ListItem>();
        for (int i = 0; i < myDropdownlist.Items.Count; i++)
        {
            listItems.Add(new ListItem(myDropdownlist.Items[i].Text, myDropdownlist.Items[i].Value));
        }
        myDropdownlist.Items.Clear();
        for (int i = listItems.Count - 1; i >= 0; i--)
        {
            myDropdownlist.Items.Add(new ListItem(listItems[i].Text, listItems[i].Value));
        }
    }