function mark_word(bodyText, searchTerm, highlightStartTag, highlightEndTag) 
{
  // the highlightStartTag and highlightEndTag parameters are optional
  if ((!highlightStartTag) || (!highlightEndTag)) {
    highlightStartTag = "<span style='color:blue; background-color:yellow;'>";
    highlightEndTag = "</span>";
  }
  

  var newText = '';
  var i = -1;
  var lcSearchTerm = searchTerm.toLowerCase();
  var lcBodyText = bodyText.toLowerCase();
    
  while (bodyText.length > 0) {
    i = lcBodyText.indexOf(lcSearchTerm, i+1);
    if (i < 0) {
      newText += bodyText;
      bodyText = '';
    } else {
      // skip anything inside an HTML tag
      if (bodyText.lastIndexOf('>', i) >= bodyText.lastIndexOf('<', i)) {
        // skip anything inside a <script> block
        if (lcBodyText.lastIndexOf('/script>', i) >= lcBodyText.lastIndexOf('<script', i)) {
          newText += bodyText.substring(0, i) + highlightStartTag + bodyText.substr(i, searchTerm.length) + highlightEndTag;
          bodyText = bodyText.substr(i + searchTerm.length);
          lcBodyText = bodyText.toLowerCase();
          i = -1;
        }
      }
    }
  }			  
  return newText;
}