/* 
Smooth Scroll 2009-05-01
*/

var ssObj = {
  setAllLinks : function() {
    var allLinks = document.getElementsByTagName('a');
    for (var i=0;i<allLinks.length;i++) {
      var linkTrg = allLinks[i];

      if ((linkTrg.href && linkTrg.href.indexOf('#anchor') != -1) && 
	 	 ((linkTrg.pathname == location.pathname) || ('/'+linkTrg.pathname == location.pathname)) && 
	 	 (linkTrg.search == location.search)) {
        ssObj.addEvent(linkTrg,'click',ssObj.smoothScroll);
      }
    }
  },

	//'click' event handler
  smoothScroll : function(e) {
    if (window.event) {  	//for ie
      target = window.event.srcElement;
    } else if (e) {
      target = e.target;
    } else {
		return;
	}
	
    if (target.nodeName.toLowerCase() != 'a') {
      target = target.parentNode;
    }
  	if (target.nodeName.toLowerCase() != 'a') return;
  
    anchor = target.hash.substr(1);
    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 (!destinationLink) return true;
  
    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;
    }
  
    clearInterval(ssObj.INTERVAL);
  
    cypos = ssObj.getCurrentYPos();
  
    ssObj_stepsize = parseInt((desty-cypos)/ssObj.STEPS);
    ssObj.INTERVAL =
	setInterval('ssObj.scrollWindow('+ssObj_stepsize+','+desty+',"'+anchor+'")',10);
  
    // click event end
    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 = ssObj.getCurrentYPos();
    isAbove = (wascypos < dest);
    window.scrollTo(0,wascypos + scramount);
    iscypos = ssObj.getCurrentYPos();
    isAboveNow = (iscypos < dest);
    if ((isAbove != isAboveNow) || (wascypos == iscypos)) {
      window.scrollTo(0,dest);
      clearInterval(ssObj.INTERVAL);
      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) {
    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");
    }
  } 
}

ssObj.STEPS = 25;
ssObj.addEvent(window,"load",ssObj.setAllLinks);