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("*");
      for (i=0;i<anchors.length;i++) {
            if (anchors[i].name == aname || anchors[i].id == 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;
} 

/* offset calculation functions from quirksmode */

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;
}