OnProgressChange fires when the progress of a download operation is updated. 
The event handler is used to provide visual feedback about the download process. For example, an OnProgressChange event handler can update a TProgressBar component or display the number of bytes downloaded so far.

Command Arguments:

Sender

The TEmbeddedWB component for which the event is being generated. Usage: (Sender as TEmbeddedWB)

Progress

Total progress made so far (number of bytes). -1 if complete.

ProgressMax

Maximum progress value (number of bytes.)

procedure TbrowserFrm.WB1ProgressChange(ASender: TObject; Progress,
  ProgressMax: Integer);
begin
   If (Progress>=1) and (ProgressMax>1)
    then
       begin
         ProgressBar1.Visible  := True;
         ProgressBar1.Position := Round((Progress * 100) Div ProgressMax);
         StatusBar1.Panels[1].Caption  := Format('%d %', [Progress Div 100]);
        end
   else
      begin
          ProgressBar1.Position := 1;
          StatusBar1.Panels[4].Caption:='';
          ProgressBar1.Visible  := False;
      end;
end;