var scrollInt;
var scrTime, scrSt, scrDist, scrDur, scrInt;
	
function replaceAnchorLinks()
{
	var anchors, i, targ, targarr;

	if (!document.getElementById)
		return;
	
	// get all anchors
	anchors = document.getElementsByTagName("a");
	
	for (i=0;i<anchors.length;i++)
	{
	
		// check if href links to an anchor on this page
		if ( anchors[i].href.indexOf("#") != -1 && anchors[i].href.indexOf( document.URL ) != -1 )
		{
			// get name of target anchor
			targ = anchors[i].href.substring( anchors[i].href.indexOf("#")+1 );
			
			// find target anchor
			targarr = document.getElementsByName( targ );
			
			if (targarr.length)
			{
				anchors[i].id = "__" + targ;	// save target as id with prefix (used in onclick function below)
				anchors[i].onmousedown = function () { scrollToAnchor( this.id.substring( 2 ) ); return false; };
				anchors[i].href = "#";			// rewrite href
			}
		}
		
	}
}	

/*
SCROLL FUNCTIONS
*/

function scrollPage()
{
	scrTime += scrInt;
	if (scrTime < scrDur) {
		window.scrollTo( 0, easeInOut(scrTime,scrSt,scrDist,scrDur) );
	}else{
		window.scrollTo( 0, scrSt+scrDist );
		clearInterval(scrollInt);
	}
}

function scrollToAnchor(aname)
{
	var anchors, i, ele;

	if (!document.getElementById)
		return;
	
	// get anchor
	anchors = document.getElementsByTagName("a");
	for (i=0;i<anchors.length;i++) {
		if (anchors[i].name == aname) {
			ele = anchors[i];
			i = anchors.length;
		}
	}
	
	// set scroll target
	if (window.scrollY)
		scrSt = window.scrollY;
	else if (document.documentElement.scrollTop)
		scrSt = document.documentElement.scrollTop;
	else
		scrSt = document.body.scrollTop;

	scrDist = findPosY(ele) - scrSt;
	scrDur = 500;
	scrTime = 0;
	scrInt = 10;
	
	// set interval
	clearInterval(scrollInt);
	scrollInt = setInterval( scrollPage, scrInt );
}

/*
EASING FUNCTIONS
*/

function easeInOut(t,b,c,d)
{
	return c/2 * (1 - Math.cos(Math.PI*t/d)) + b;
}

function findPosY(obj)
{
  var curtop = 0;

  if (obj.offsetParent)
  {
    while (obj.offsetParent)
    {
      curtop += obj.offsetTop
      obj = obj.offsetParent;
    }
  }
  else if (obj.y)
  curtop += obj.y;

  return curtop;
}