csrf token validation failed when i try to add X-CSRF-Token to Request Header in OData

Hi,

I am creating a WCF rest service to consume SAP OData service in my application i am able to read data but not able to insert entity.

I am getting an issue while add X-CSRF-Token to Entity Request Header. Please help me on this.

                    var cookieContainer = new CookieContainer();

                    cookieContainer.Add(new Cookie("SAP_SESSIONID", "value"){Domain= Uri.Host});

                var entities = new ServiceReference1.leaverequest_Entities(sapUri);

                entities.Credentials = new NetworkCredential("username", "password");

                entities.SendingRequest += (s, e) =>

                {

                    ((HttpWebRequest)e.Request).CookieContainer = cookieContainer;

                    ((HttpWebRequest)e.Request).Headers.Add("X-CSRF-Token", csrfToken);

                };

                entities.AddToLeaveRequestCollection(leaveRequest);               

                entities.SaveChanges();

I wrote unit test for debug my POST implementation. When i am debugging the code , when ever "((HttpWebRequest)e.Request).Headers.Add("X-CSRF-Token", csrfToken)" code executing , i am getting exception that "csrf token validation failed".

Need a help on this Urgent?

Thanks,

Siva