How to create announcement box in asp.net?

If u want message box use following


public static void ShowAlertMessage(string error)
{

Page page = HttpContext.Current.Handler as Page;

if (page != null)
{

error = error.Replace("'", "\'");

ScriptManager.RegisterStartupScript(page, page.GetType(), "err_msg", "alert('" + error + "');", true);

}
}