/* This script and many more are available free online at
The JavaScript Source :: http://javascript.internet.com
Created by: Stuart Langridge :: http://www.kryogenix.org/ */

// Licenced under the MIT licence

function highlightWord(node,word) {
  // Iterate into this nodes childNodes
  if (node.hasChildNodes) {
    var hi_cn;
    for (hi_cn=0;hi_cn<node.childNodes.length;hi_cn++) {
      highlightWord(node.childNodes[hi_cn],word);
    }
  }

  // And do this node itself
  if (node.nodeType == 3) { // text node
    tempNodeVal = node.nodeValue.toLowerCase();
    tempWordVal = word.toLowerCase();
    if (tempNodeVal.indexOf(tempWordVal) != -1) {
      pn = node.parentNode;
      if (pn.className != "searchword") {
        // word has not already been highlighted!
        nv = node.nodeValue;
        ni = tempNodeVal.indexOf(tempWordVal);
        // Create a load of replacement nodes
        before = document.createTextNode(nv.substr(0,ni));
        docWordVal = nv.substr(ni,word.length);
        after = document.createTextNode(nv.substr(ni+word.length));
        hiwordtext = document.createTextNode(docWordVal);
        hiword = document.createElement("span");
        hiword.className = "searchword";
        hiword.appendChild(hiwordtext);
        pn.insertBefore(before,node);
        pn.insertBefore(hiword,node);
        pn.insertBefore(after,node);
        pn.removeChild(node);
      }
    }
  }
}

function googleSearchHighlight() {
  if (!document.createElement) return;
  ref = document.referrer;
  if (ref.indexOf('?') == -1) return;
  qs = ref.substr(ref.indexOf('?')+1);
  qsa = qs.split('&');
  for (i=0;i<qsa.length;i++) {
    qsip = qsa[i].split('=');
    if (qsip.length == 1) continue;
    if (qsip[0] == 'q' || qsip[0] == 'p') { // q= for Google, p= for Yahoo
      words = unescape(qsip[1].replace(/\+/g,' ')).split(/\s+/);
      for (w=0;w<words.length;w++) {
         highlightWord(document.getElementsByTagName("body")[0],words[w]);
      }
    }
  }
}

window.onload = googleSearchHighlight;