bdgrid+dataset to excel

procedure TForm1.btnExportClick(Sender: TObject);
var
  ExpClass:TDBGridEhExportClass;
  Ext:string;
begin
  SaveDialog1.FileName := 'file1';
  //if (ActiveControl is TDBGridEh) then
  if SaveDialog1.Execute then
  begin
    case SaveDialog1.FilterIndex of
      1: begin ExpClass := TDBGridEhExportAsText; Ext := 'txt'; end;
      2: begin ExpClass := TDBGridEhExportAsCSV; Ext := 'csv'; end;
      3: begin ExpClass := TDBGridEhExportAsHTML; Ext := 'htm'; end;
      4: begin ExpClass := TDBGridEhExportAsRTF; Ext := 'rtf'; end;
      5: begin ExpClass := TDBGridEhExportAsXLS; Ext := 'xls'; end;
    else
      ExpClass := TDBGridEhExportAsXLS; Ext := 'xls';
    end;
    if ExpClass <> nil then
    begin
      if UpperCase(Copy(SaveDialog1.FileName,Length(SaveDialog1.FileName)-2,3)) <>
                    UpperCase(Ext) then
        SaveDialog1.FileName := SaveDialog1.FileName + '.' + Ext;
      SaveDBGridEhToExportFile(ExpClass,DBGridEh1,SaveDialog1.FileName,True);
    end;
  end;
end;

 uses Comobj