Hi , I am Using Umbraco v 7.15.1 . and i m newbie too

We have Create the usercontrol seprate While integrated the usercontrol it shows Some error

Server Error in '/' Application. Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.] System.Web.UI.PageRequestManager.RenderPageRequestManagerScript(HtmlTextWriter writer) +92 System.Web.UI.PageRequestManager.Render(HtmlTextWriter writer) +39 System.Web.UI.ScriptManager.Render(HtmlTextWriter writer) +106 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +129 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +285 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +27 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +197 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +9 System.Web.UI.Control.Render(HtmlTextWriter writer) +10 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +129 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +285 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +27 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +197 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +9 System.Web.UI.Page.Render(HtmlTextWriter writer) +30 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +129 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +285 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +27 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5616

when i try to add a form tag in the Usercontrol UI is Working But Server call Is not happen

When The same When i try to add form tag in master page Its Not working Can you please guide me How to implement It