var barposition = 0;
var barspeed = 8;
var bardiff = 270;
var slidebar = document.getElementById('slidebar');
var barmin = 0;
var barmax = -(slidebar.scrollWidth - bardiff);
var barwidth = width_slidepic + (count_slidepic - 1) * 2 + count_slidepic * 2;

var aktiv;

endArrow('leftslide');

if (barwidth < barmax)
{
  document.getElementById('rightslide_a').style.display = 'none';
  document.getElementById('leftslide_a').style.display = 'none';
}

function stopSlide() {
    window.clearInterval(aktiv);
}

function setSlideLeft() {
  if (barwidth > barmax)
  {
    barmax = -(slidebar.scrollWidth - bardiff);
    aktiv = window.setInterval("SlideLeft()", barspeed);
  }
}

function SlideLeft() {
  if (barwidth > barmax)
  {
    if (barposition <= barmax) {
        barposition = barmax;
        endArrow('rightslide');
        startArrow('leftslide');
    } else {
        barposition = barposition - 1;
        startArrow('leftslide');
    }
    slidebar.style.left =  barposition + 'px';
  }
}

function setSlideRight() {
  if (barwidth > barmax)
  {
    barmax = -(slidebar.scrollWidth - bardiff);
    aktiv = window.setInterval("SlideRight()", barspeed);
  }
}

function SlideRight() {
  if (barwidth > barmax)
  {
    if (barposition >= barmin) {
        //alert('barposition = ' + barposition + "\r\n" + 'barmin = ' + barmin);
        barposition = 0;
        endArrow('leftslide');
        startArrow('rightslide');
    } else {
        barposition = barposition + 1;
        startArrow('rightslide');
    }
    slidebar.style.left =  barposition + 'px';
  }
}

function endArrow(id) {
  document.getElementById(id).className = 'slightarrow_light';
}

function startArrow(id) {
  document.getElementById(id).className = 'slightarrow_full';
}