Adding New items in DropDown

 <asp:DropDownList ID="drpdwn" runat="server"></asp:DropDownList>

protected void Page_Load(object sender, EventArgs e)
    {
        if(!IsPostBack)
        for (int i = 0; i < 5; i++)
        {
            drpdwn.Items.Add(new ListItem("Item" + i, i.ToString()));
        }
            drpdwn.Items.Insert(3, new ListItem("Item -1", "3" ));
        
    }