var interval = 0;
var promo_ch = 0;
var promo_interval = 0;

var bgColor1 = '#FFF';
var bgColor2 = '#D4DCE9';

function promo_hide_all(){
  document.getElementById('promo1').style.display = 'none';
  document.getElementById('promo2').style.display = 'none';
  document.getElementById('promo3').style.display = 'none';
  document.getElementById('promo4').style.display = 'none';
};

function promo_bg_dark_all(){
  document.getElementById('promoa1').style.backgroundColor = bgColor1;
  document.getElementById('promoa2').style.backgroundColor = bgColor1;
  document.getElementById('promoa3').style.backgroundColor = bgColor1;
  document.getElementById('promoa4').style.backgroundColor = bgColor1;
};


function promo_change(){
  promo_ch++;
  if(promo_ch>4) {promo_ch = 1;}
  promo_hide_all();
  promo_bg_dark_all();
  document.getElementById('promo'+promo_ch).style.display = 'block';
  document.getElementById('promoa'+promo_ch).style.backgroundColor = bgColor2;
  promo_interval = setTimeout(function(){promo_change();}, 8*1000);
}


window.onload = function(){
  banner_4_belt = document.getElementById('banner-4-belt');
  setTimeout(function(){scroll('-1', 'banner-4-belt', '66');}, 10);
  
  banner_2_belt = document.getElementById('banner-2-belt');
  setTimeout(function(){scroll('-1', 'banner-2-belt', '66');}, 10);
  
  banner_3_belt = document.getElementById('banner-3-belt');
  setTimeout(function(){scroll('-1', 'banner-3-belt', '240');}, 10);
  
  banner_5_belt = document.getElementById('banner-5-belt');
  setTimeout(function(){scroll('-1', 'banner-5-belt', '66');}, 10);

  document.getElementById('promoa1').onclick = function(){
    promo_hide_all();
    promo_bg_dark_all();
    document.getElementById('promo1').style.display = 'block';
    document.getElementById('promoa1').style.backgroundColor = bgColor2;
  };
  document.getElementById('promoa2').onclick = function(){
    promo_hide_all();
    promo_bg_dark_all();
    document.getElementById('promo2').style.display = 'block';
    document.getElementById('promoa2').style.backgroundColor = bgColor2;
  };
  document.getElementById('promoa3').onclick = function(){
    promo_hide_all();
    promo_bg_dark_all();
    document.getElementById('promo3').style.display = 'block';
    document.getElementById('promoa3').style.backgroundColor = bgColor2;
  };
  document.getElementById('promoa4').onclick = function(){
    promo_hide_all();
    promo_bg_dark_all();
    document.getElementById('promo4').style.display = 'block';
    document.getElementById('promoa4').style.backgroundColor = bgColor2;
  };
  
  promo_change();
  
};


function scroll(kam, co, vyska){
  oY = 1;
  cas = 100;
  
  top2 = document.getElementById(co).style.top;
  top2 = top2.substring(0,top2.length-2);
  if( (-1*top2 > document.getElementById(co).scrollHeight - vyska) || (top2 > 0) ){
    cas = 1000;
    kam*=-1;
  }
  
  top2 = Number(top2)+kam*oY;
  document.getElementById(co).style.top = top2 + 'px';
  
  interval = setTimeout(function(){scroll(kam, co, vyska);}, cas);
}