//  add onload
function addLoadAnim(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}





//  opacity functions
  
function SetOpacity(elem, opacityAsInt)
{
	var opacityAsDecimal = opacityAsInt;
	
	if (opacityAsInt > 100)
		opacityAsInt = opacityAsDecimal = 100; 
	else if (opacityAsInt < 0)
		opacityAsInt = opacityAsDecimal = 0; 
	
	opacityAsDecimal /= 100;
	if (opacityAsInt < 1)
		opacityAsInt = 1; // IE7 bug, text smoothing cuts out if 0
	
	elem.style.opacity = opacityAsDecimal;
	elem.style.filter  = "alpha(opacity=" + opacityAsInt + ")";
}

function FadeOpacity(elemId, fromOpacity, toOpacity, time, fps)
{
	var steps = Math.ceil(fps * (time / 1000));
	var delta = (toOpacity - fromOpacity) / steps;
	
	FadeOpacityStep(elemId, 0, steps, fromOpacity, delta, (time / steps));
}

function FadeOpacityStep(elemId, stepNum, steps, fromOpacity, delta, timePerStep)
{
    SetOpacity(document.getElementById(elemId), Math.round(parseInt(fromOpacity) + (delta * stepNum)));

    if (stepNum < steps)
        setTimeout("FadeOpacityStep('" + elemId + "', " + (stepNum+1) + ", " + steps + ", " + fromOpacity + ", " + delta + ", " + timePerStep + ");", timePerStep);
}


/* prima funkce na hlavni */
function AnimaceStart() {

  var time = 2000;
  
  first_duration = 1000;
  second_duration = 2500;
  third_duration = 2500;
  fourth_duration = 1000;
  
    
    setTimeout( 'FadeOpacity("anim_2",0,100,first_duration,15)' , time );
  time += first_duration + 1000;
    
    setTimeout( 'FadeOpacity("anim_3",0,100,'+second_duration+',15);' , time );
  time += second_duration + 5000;
    
    setTimeout( 'FadeOpacity("anim_3",100,0,'+third_duration+',15);' , time );
  time += third_duration + 2000;
       
    setTimeout( 'FadeOpacity("anim_2",100,0,'+fourth_duration+',15);' , time );
  
}

function AnimaceOn() {

  SetOpacity(document.getElementById("anim_1"),100);
  SetOpacity(document.getElementById("anim_2"),0);
  SetOpacity(document.getElementById("anim_3"),0);
  
AnimaceStart();
setInterval('AnimaceStart()',18000);

}