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


function changeBg(){
    $('header_img').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').setStyles({
        'filter':'alpha(opacity=1)',
        '-moz-opacity': '1',
        'opacity': '1'
    })
    if (imageObj.length > fadeNr+1) {
         fadeNr++;
    } else {
        fadeNr = 0;
    }
    $('headergb').setStyle('background-image','url('+imageObj[fadeNr].src+')');
}

function changeImg() {
  if (counterI == 0) {
     counterI=1
     changeBg()
  }else if (counterI == 1){

    fadeIn()
    counterI=2;
      
  }else{
    fadeOut()
    counterI=0;
  }
  
      

}

var aktiv = window.setInterval("changeImg()", 1500);