/*
* This is the function that actually highlights a text string by
* adding HTML tags before and after all occurrences of the search
* term. You can pass your own tags if you'd like, or if the
* highlightStartTag or highlightEndTag parameters are omitted or
* are empty strings then the default <font> tags will be used.
*/

function doHighlight(bodyText, searchTerm, highlightStartTag, highlightEndTag) 
{
	
// the highlightStartTag and highlightEndTag parameters are optional
if ((!highlightStartTag) || (!highlightEndTag)) {
highlightStartTag = "<font name=highlighted_text style='color:white; background-color:#006699;' font-family=arial>";
highlightEndTag = "</font>";
}

// find all occurences of the search term in the given text,
// and add some "highlight" tags to them (we're not using a
// regular expression search, because we want to filter out
// matches that occur within HTML tags and script blocks, so
// we have to do a little extra validation)
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;
}


  function clearHighlightedSpans() {
    var celem=document.getElementsByTagName("font");
    if (celem) {
        for (var i=celem.length-1;i>-1;i--) {
            if (celem[i].getAttribute("name")=="highlighted_text") {
                var s=celem[i].innerHTML;
                var otxt=document.createTextNode(s)
                celem[i].parentNode.insertBefore(otxt,celem[i]);
                celem[i].parentNode.removeChild (celem[i]);
            }
        }
    }
}


/*
 * This is sort of a wrapper function to the doHighlight function.
 * It takes the searchText that you pass, optionally splits it into
 * separate words, and transforms the text on the current web page.
 * Only the "searchText" parameter is required; all other parameters
 * are optional and can be omitted.
 */

 
function highlightSearchTerms(searchText, treatAsPhrase, warnOnFailure, highlightStartTag, highlightEndTag)
{
  // if the treatAsPhrase parameter is true, then we should search for 
  // the entire phrase that was entered; otherwise, we will split the
  // search string so that each word is searched for and highlighted
  // individually

    clearHighlightedSpans();
  
  if (treatAsPhrase) {
    searchArray = [searchText];
  } else {
    searchArray = searchText.split(" ");
  }
  
  if (!document.body || typeof(document.body.innerHTML) == "undefined") {
    if (warnOnFailure) {
      alert("Sorry, for some reason the text of this page is unavailable. Searching will not work.");
    }
    return false;
  }

  var bodyText = document.body.innerHTML;
  for (var i = 0; i < searchArray.length; i++) {
    bodyText = doHighlight(bodyText, searchArray[i], highlightStartTag, highlightEndTag);
  }
  
  document.body.innerHTML = bodyText;
  return true;
}