/* Smooth scrolling



   Changes links that link to other parts of this page to scroll



   smoothly to those links rather than jump to them directly, which



   can be a little disorienting.



   



   sil, http://www.kryogenix.org/



   



   v1.0 2003-11-11



   v1.1 2005-06-16 wrap it up in an object



*/







var ss = {



  fixAllLinks: function() {



    // Get a list of all links in the page



    var allLinks = document.getElementsByTagName('a');



    // Walk through the list



    for (var i=0;i<allLinks.length;i++) {



      var lnk = allLinks[i];



      if ((lnk.href && lnk.href.indexOf('#') != -1) && 



          ( (lnk.pathname == location.pathname) ||



	    ('/'+lnk.pathname == location.pathname) ) && 



          (lnk.search == location.search)) {



        // If the link is internal to the page (begins in #)



        // then attach the smoothScroll function as an onclick



        // event handler



        ss.addEvent(lnk,'click',ss.smoothScroll);



      }



    }



  },







  smoothScroll: function(e) {



    // This is an event handler; get the clicked on element,



    // in a cross-browser fashion



    if (window.event) {



      target = window.event.srcElement;



    } else if (e) {



      target = e.target;



    } else return;







    // Make sure that the target is an element, not a text node



    // within an element



    if (target.nodeName.toLowerCase() != 'a') {



      target = target.parentNode;



    }



  



    // Paranoia; check this is an A tag



    if (target.nodeName.toLowerCase() != 'a') return;



  



    // Find the <a name> tag corresponding to this href



    // First strip off the hash (first character)



    anchor = target.hash.substr(1);



    // Now loop all A tags until we find one with that name



    var allLinks = document.getElementsByTagName('a');



    var destinationLink = null;



    for (var i=0;i<allLinks.length;i++) {



      var lnk = allLinks[i];



      if (lnk.name && (lnk.name == anchor)) {



        destinationLink = lnk;



        break;



      }



    }



    if (!destinationLink) destinationLink = document.getElementById(anchor);







    // If we didn't find a destination, give up and let the browser do



    // its thing



    if (!destinationLink) return true;



  



    // Find the destination's position



    var destx = destinationLink.offsetLeft; 



    var desty = destinationLink.offsetTop;



    var thisNode = destinationLink;



    while (thisNode.offsetParent && 



          (thisNode.offsetParent != document.body)) {



      thisNode = thisNode.offsetParent;



      destx += thisNode.offsetLeft;



      desty += thisNode.offsetTop;



    }



  



    // Stop any current scrolling



    clearInterval(ss.INTERVAL);



  



    cypos = ss.getCurrentYPos();



  



    ss_stepsize = parseInt((desty-cypos)/ss.STEPS);



    ss.INTERVAL =



setInterval('ss.scrollWindow('+ss_stepsize+','+desty+',"'+anchor+'")',10);



  



    // And stop the actual click happening



    if (window.event) {



      window.event.cancelBubble = true;



      window.event.returnValue = false;



    }



    if (e && e.preventDefault && e.stopPropagation) {



      e.preventDefault();



      e.stopPropagation();



    }



  },







  scrollWindow: function(scramount,dest,anchor) {



    wascypos = ss.getCurrentYPos();



    isAbove = (wascypos < dest);



    window.scrollTo(0,wascypos + scramount);



    iscypos = ss.getCurrentYPos();



    isAboveNow = (iscypos < dest);



    if ((isAbove != isAboveNow) || (wascypos == iscypos)) {



      // if we've just scrolled past the destination, or



      // we haven't moved from the last scroll (i.e., we're at the



      // bottom of the page) then scroll exactly to the link



      window.scrollTo(0,dest);



      // cancel the repeating timer



      clearInterval(ss.INTERVAL);



      // and jump to the link directly so the URL's right



      location.hash = anchor;



    }



  },







  getCurrentYPos: function() {



    if (document.body && document.body.scrollTop)



      return document.body.scrollTop;



    if (document.documentElement && document.documentElement.scrollTop)



      return document.documentElement.scrollTop;



    if (window.pageYOffset)



      return window.pageYOffset;



    return 0;



  },







  addEvent: function(elm, evType, fn, useCapture) {



    // addEvent and removeEvent



    // cross-browser event handling for IE5+,  NS6 and Mozilla



    // By Scott Andrew



    if (elm.addEventListener){



      elm.addEventListener(evType, fn, useCapture);



      return true;



    } else if (elm.attachEvent){



      var r = elm.attachEvent("on"+evType, fn);



      return r;



    } else {



      alert("Handler could not be removed");



    }



  } 



}







ss.STEPS = 25;







ss.addEvent(window,"load",ss.fixAllLinks);