function random_value() {
  var digits = '0987654321';
  var lowers = 'abcdefghijklmnopqrstuvwxyz';
  var chars = digits+lowers;
  var random = '';
  var strlen = 8;
  var length = chars.length;
  num = Math.round(Math.random()*(lowers.length-1));
  random += lowers.charAt(num);
  for (var i=0; i<strlen-1; i++) {
    num = Math.round(Math.random()*(length-1));
    random += chars.charAt(num);
  }
  return random;
}