如何访问不在当前目录下的dbf文件？

Question

var
    m_filenamepath:string;         //文件全路经   ；
begin
 if  OpenDialog.Execute then    begin
      m_filenamepath:=OpenDialog.FileName;
      m_filename := ExtractFileName(m_filenamepath);
      m_filedirpath:=ExtractFilePath(m_filenamepath);
      if  m_filename='' then exit;
      screen.Cursor:=crhourglass;        try
              begin
               if table.Active then
               table.Close;
               table.databasename := m_filedirpath;
               table.TableName:=  m_filename;
               table.Open;
       bl_openfile1:=true;      //打开了文件
       m_i:=table.FieldDefs.Count;
               grid.DataSource:=datasouce;
               screen.Cursor:=crdefault;               StatusBar.SimpleText:= '共有' + intToStr(table.RecordCount) + '条纪录'   ;
             end;
        except
          screen.Cursor:=crdefault;
          application.MessageBox('打开表错误,请打开表重试.','表索引错误',mb_defbutton1) ;        end;   //try结束
    end;