var backgroundImages = new Array();
for(var i = 0; i < 5; i++) {
        backgroundImages[i] = new Image();
        backgroundImages[i].src = '/img/header_image_0' + (i + 1) + '.jpg';
}

function changeBackground() {
        var availableBackgrounds = ['backgroundImage1','backgroundImage2','backgroundImage3','backgroundImage4','backgroundImage5'];
        var oldBackgroundElement = document.getElementById('background');
        var oldBackground = oldBackgroundElement.alt;

        var randomIndex = Math.round(Math.random() * (availableBackgrounds.length - 1));
        var i = 0;
        while(availableBackgrounds[randomIndex] == oldBackground) {
                if(i > 10)
                        break;
                randomIndex = Math.round(Math.random() * (availableBackgrounds.length - 1));
                i++;
        }
        jQuery('#background').fadeOut(800,function(){
                oldBackgroundElement.src = backgroundImages[randomIndex].src;
                jQuery('#background').fadeIn(800);
                oldBackgroundElement.alt = availableBackgrounds[randomIndex];
        });
}

function setChange() {

	setInterval ( "changeBackground()", 10000 );

}