Render user control in PageMethod

I want to render a user control in pagemethod and return the html back to client. But its getting annoying, I tried like many ways but nothing found working. The problem is that, the usercontrol require both HtmlHead and ScriptManager.


I tried this but it doesn't work(raise error : ScriptManger require in page) because ScriptManager must be inside HtmlForm but Page.Form always null.
[WebMethod] public static string GetControl(int topicID) { XPage page = new XPage(); page.Controls.Add(new HtmlHead()); page.Controls.Add(new ScriptManager()); //must be in page.Form.Control UserControl123 cdl = (UserControl123)page.LoadControl("/UserControl123.ascx"); pageHolder.Controls.Add(cdl); //HtmlTextWriter htextWRiter = new HtmlTextWriter(new System.IO.StringWriter()); //cdl.RenderControl(htextWRiter); //htextWRiter.Close(); //htextWRiter.ToString(); StringWriter output = new StringWrit ...