public int CompareTo(object obj) // to implement the IComparable interface
        {
            DXMemRecord rec = (DXMemRecord)obj;

            if (this.DXURL != rec.DXURL)
            {
                return(this.DXURL.CompareTo(rec.DXURL));
            }



            return(this.DXURL.CompareTo(rec.DXURL));
        } // compareto
 public DXMemRecord(DXMemRecord rec)
 {
     dxurl = rec.dxurl;
 }