c# WebRequest HttpBehaviour error

guys. I wrote some code:

        this.req = (HttpWebRequest)WebRequest.Create(this._urlNBKIMain);
        this.req.Accept = this._accept;
        this.req.Headers.Add(this._acceptLanguage);
        this.req.UserAgent = this._userAgent;
        this.req.Host = this._hostNBKI;
        this.req.KeepAlive = this._keepAlive;
        this.req.AutomaticDecompression = (DecompressionMethods.GZip | DecompressionMethods.Deflate);
        this.req.CookieContainer = this.cookieContainer;
        ServicePoint servicePoint = this.req.ServicePoint;
        PropertyInfo property = servicePoint.GetType().GetProperty("HttpBehaviour", BindingFlags.Instance | BindingFlags.NonPublic);
        property.SetValue(servicePoint, 0, null);
        this.res = (HttpWebResponse)this.req.GetResponse();

But, I got runtime error:

System.ArgumentException: It is not possible to convert an object of type "System.Int32" to type "System.Net.HttpBehaviour". in System.RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast) in System.RuntimeType.CheckValue(Object value, Binder binder, CultureInfo culture, BindingFlags invokeAttr) in System.Reflection.MethodBase.CheckArguments(Object[] parameters, Binder binder, BindingFlags invokeAttr, CultureInfo culture, Signature sig) in System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) in System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) in System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture) in System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index) in CheckNBKI.GetMainFormNBKI()

Help me, please.