var clipTop = 0;
var clipWidth = 350;
var clipBottom = 400;
var topper = 55;
var lyrheight = 0;
var time,amount,theTime,theHeight,DHTML;
function getObj(name)
{
  if (document.getElementById)
  {
        this.obj = document.getElementById(name);
        this.style = document.getElementById(name).style;
  }
  else if (document.all)
  {
        this.obj = document.all[name];
        this.style = document.all[name].style;
  }
  else if (document.layers)
  {
        this.obj = document.layers[name];
        this.style = document.layers[name];
  }
} 
function init()
{
        DHTML = (document.getElementById || document.all || document.layers)
        if (!DHTML) return;
        var x = new getObj('example');
        if (document.layers)
        {
                lyrheight = x.style.clip.bottom;
                lyrheight += 20;
                x.style.clip.top = clipTop;
                x.style.clip.left = 0;
                x.style.clip.right = clipWidth;
                x.style.clip.bottom = clipBottom;
        }
        else if (document.getElementById || document.all)
        {
                lyrheight = x.obj.offsetHeight;
                x.style.clip = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
        }
}

function scrollayer(layername,amt,tim)
{
        if (!DHTML) return;
        thelayer = new getObj(layername);
        if (!thelayer) return;
        amount = amt;
        theTime = tim;
        realscroll();
}

function realscroll()
{
        if (!DHTML) return;
        clipTop += amount;
        clipBottom += amount;
        topper -= amount;
        if (clipTop < 0 || clipBottom > lyrheight)
        {
                clipTop -= amount;
                clipBottom -= amount;
                topper += amount;
                return;
        }
        if (document.getElementById || document.all)
        {
                clipstring = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
                thelayer.style.clip = clipstring;
                thelayer.style.top = topper;
        }
        else if (document.layers)
        {
                thelayer.style.clip.top = clipTop;
                thelayer.style.clip.bottom = clipBottom;
                thelayer.style.top = topper;
        }
        time = setTimeout('realscroll()',theTime);
}

function stopScroll()
{
        if (time) clearTimeout(time);
}