if(Date.parse(document.lastModified) != 0)
   document.write('<p><hr><small><i>'
                  + 'Rev. 6.1.1 '
                  + '<br>Last modified: '
                  + document.lastModified
                  + '<br>© 1986-2011: Minze Stuiver and Paula Reimer'
                  + '</i></small>');