// PlaceHolder Control //////////////////////////////////
<asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>

// Populates the PlaceHolder control //////////////////////////////////
private void PopulatePlaceHolder()
    {
        // Add ASP.NET Server Control
        TextBox txt1 = new TextBox();
        txt1.ID = "txt1";
        txt1.Width = 300;
        txt1.Text = "This control added from Server side.";
        PlaceHolder1.Controls.Add(txt1);

        // Add HTML controls
        string strHTML = "<hr /><table border='1'><tr><td>This contorl and outer HTML Table also added from Server side</td></tr><tr><td><input type='text' name='txtname' id='txtname' /></td></tr></table>";
        PlaceHolder1.Controls.Add(new LiteralControl(strHTML));
        
        // Add the usercontrol dynamically
        Control webUserControl = (Control)Page.LoadControl("~/tutorials/controls/controldata/WebUserControl.ascx");
        PlaceHolder1.Controls.Add(webUserControl);
    }