Datagris edit cell problems

reply, class structure should be such. 

public class Kisi : INotifyPropertyChanged

    {

        private int id { get; set; }

        private string adSoyad { get; set; }

        private string gsm { get; set; }

        public event PropertyChangedEventHandler PropertyChanged;

        private void RaisePropertyChanged(String Name)

        {

            if (PropertyChanged != null)

                this.PropertyChanged(this, new PropertyChangedEventArgs(Name));

        }

        public int Id

        {

            get { return id; }

            set { this.id = value; RaisePropertyChanged("Id"); }

        }

        public string AdSoyad

        {

            get { return adSoyad; }

            set { this.adSoyad = value; RaisePropertyChanged("AdSoyad"); }

        }

        public string Gsm

        {

            get { return gsm; }

            set { this.gsm = value; RaisePropertyChanged("Gsm"); }

        }

    }