var effectspeed = 1000;
var fadeNr = new Number(0);
var counterI = 0


function changeBg(){
    if (imageObj.length > fadeNr+1) {
         fadeNr++;
    } else {
        fadeNr = 0;
    }
	$('header_img_bg').src= imageObj[fadeNr].src;
}

function fadeOut(){
        var hide = new Fx.Morph($('header_img'), {duration: 1500, transition: Fx.Transitions.linear});

        hide.start({
            'filter':'alpha(opacity=0)',
            '-moz-opacity': '0',
            'opacity': '0'
        });

}

function fadeIn(){
    $('header_img').src= $('header_img_bg').src
   $('header_img').setStyles({
		'filter':'alpha(opacity=1)',
		'-moz-opacity': '1',
		'opacity': '1'
	})   	
}

function changeImg() {
  if (counterI == 0) {
     counterI=1
     changeBg()
  }else if(counterI==1) {
     counterI=2;
     fadeOut()
  }else if(counterI==2){
     fadeIn()
     counterI=0;
  }
}

var aktiv = window.setInterval("changeImg()", 4000);