Using Interface in Class

class Clsample    {
        #region Declarations

      
        ISample    l_SampleUpl;

        #endregion

        #region Constructor

        public ClsBankCodeFCCRMUpld( ISample    ISmplUpl)
        {
             l_SampleUpl = ISmplUpl;
        }





 public DataSet Fetchdata(out string l_errmsg)
        {
            ds = null;
            ArrayList ap = new ArrayList();
            ArrayList av = new ArrayList();
            try
            {
ap.add("FetchMode");
              av.Add( l_SampleUpl.l_FetchMode);
     ds = OracleDataAccess.oraExecProcRetDataset("pr_fetch_bankdet_fccrm", ap, av, out l_errmsg);
                return ds;
            }
            catch (Exception ex)
            {
                l_errmsg = ex.ToString();
                return ds;
            }

        }
}

 #region Interface
    public interface ISample    {
      
    }
    #endregion