function doHighlight(bodyText, searchTerm, highlightStartTag, highlightEndTag) {
  if ((!highlightStartTag) || (!highlightEndTag)) {
    highlightStartTag = "<font style='color:blue; background-color:yellow;'>";
    highlightEndTag = "</font>";
  }
  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 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;
  }
  
  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;
}

function searchPrompt(defaultText, treatAsPhrase, textColor, bgColor){
  // This function prompts the user for any words that should
  // be highlighted on this web page
  if (!defaultText) {
	defaultText = "";
  }
  
  // we can optionally use our own highlight tag values
  if ((!textColor) || (!bgColor)) {
	highlightStartTag = "";
	highlightEndTag = "";
  } else {
	highlightStartTag = "<font style='color:" + textColor + "; background-color:" + bgColor + ";'>";
	highlightEndTag = "</font>";
  }
  
  if (treatAsPhrase) {
	promptText = "Please enter the phrase you'd like to search for:";
  } else {
	promptText = "Please enter the words you'd like to search for, separated by spaces:";
  }
  
  searchText = defaultText;

  if (!searchText)  {
	alert("No search terms were entered. Exiting function.");
	return false;
  }
  
  return highlightSearchTerms(searchText, treatAsPhrase, true, highlightStartTag, highlightEndTag);
}