a 160bit digest (20bytes)</em>
    Source: TFileStream;
    i: <b>integer</b>;
    s: string;
  <b>begin</b>
    Source:= <b>nil</b>;
    <b>try</b>
      Source:= TFileStream.Create(Edit1.Text,fmOpenRead);  <em>// open the file specified by Edit1</em>
    <b>except</b>
      MessageDlg('Unable to open file',mtError,[mbOK],0);
    <b>end</b>;
    <b>if</b> Source <> <b>nil then</b>
    <b>begin</b>
      Hash:= TDCP_ripemd160.Create(Self);          <em>// create the hash</em>
      Hash.Init; 