Ragazzi chi mi aiuta a capire perché questo script non funziona?

codice:
<script language="javascript" type="text/javascript">

/* 
  linkWord(obj)
  written by Christian Heilmann (http://wait-till-i.com)
  automatically turns words defined in the object obj into 
  hyperlink. 
  The object obj sent as a paramater needs to contain all the words
  properties and the associated URLs as values.
  Demo object: 
  {
    'wait-till-i.com':'http://wait-till-i.com',
    'icant.co.uk':'http://icant.co.uk'
  }
*/
 
function linkWord(obj){
  for(i in obj){
    var x = document.body.innerHTML;
    var linkStart = '<a href="'+obj[i]+'">';     
    var linkEnd = '</a>';     
    var reg = new RegExp ('\\b' + i + '\\b','g');
    x = x.replace(reg, linkStart + i + linkEnd);
    document.body.innerHTML = x;
  }
}
  
Settings:
 
{
  'example':'http://www.example.com',
  'another':'http://icant.co.uk'
}

</script>
GRAZIE MILLE A TUTTI!!