/*
 * This is the function that actually highlights a text string by
 * adding HTML tags before and after all occurrences of the search
 * term. 
 */
 
function doHighlight(bodyText, searchTerm, highlightStartTag, highlightEndTag) 
{
  // the highlightStartTag and highlightEndTag parameters are optional
  if ((!highlightStartTag) || (!highlightEndTag)) {
    highlightStartTag = "<font style='background-color:#F0E7DE;'>";
    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) {
  	//alert(bodyText.length);
    i = lcBodyText.indexOf(lcSearchTerm, i+1);
	//alert(i);
    if (i < 0) {
      newText += bodyText;
      bodyText = "";
    } else 
    {
      
	  // skip anything inside an HTML tag
	  	
		//j=bodyText.lastIndexOf(">", i);
		//y=bodyText.lastIndexOf("<", i);
		//alert(i + ', ' + j + ', ' + y);
	  
      if (bodyText.lastIndexOf(">", i) >= bodyText.lastIndexOf("<", i))
	  	{
			// skip anything inside a <script> block
        	if (lcBodyText.lastIndexOf("/script>", i) >= lcBodyText.lastIndexOf("<script", i)) 
					{
          		/*newText wird bis zum Vorkommen des Suchbegriffes mit dem Inhalt von bodyText gefüllt, der Suchbegriff gehighlightet
          		und bodyText erhält den Rest des Textes. Das geht solange, bis bodyText 0 ist.*/
          		newText += bodyText.substring(0, i) + highlightStartTag + bodyText.substr(i, searchTerm.length) + highlightEndTag;
          		//alert (newText);
          		bodyText = bodyText.substr(i + searchTerm.length);
          		lcBodyText = bodyText.toLowerCase();
          		i = -1;
        	}
      }
    }
  }
  
  return newText;
}


/*
 * 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
  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;
  }
  
  //Suche nur innerhalb des div-tags "high"
  var bodyText = document.all.high.innerHTML;
  for (var i = 0; i < searchArray.length; i++) {
    bodyText = doHighlight(bodyText, searchArray[i], highlightStartTag, highlightEndTag);
  }
  
  document.all.high.innerHTML = bodyText;
  return true;
}