document.getElementById('top_image').src=pictures[0];

/*preloading images*/
var img=new Array();
for (var k=0;k<pictures.length;k++) {
	img[k]=new Image(227, 186);
	img[k].src=pictures[k];
} 

var count=1;	
function rotate() {//change image
	document.getElementById('top_image').src=img[count].src;
	if (document.getElementById('step')) {
		document.getElementById('step').innerHTML = 'Step ' + (count + 1);
	}
	count++;
	if (count>=pictures.length) count=0;
}

/*opacity*/
window.onload=setInterval(fade, 5000);
function fade(id, opacStart, opacEnd, millisec) { 
	var id='layer';
	var opacStart=100;
	var opacEnd=0;
	var millisec=1000;
	var speed = Math.round(millisec/100);
	var timer = 0;
  		for(j = opacEnd; j <= opacStart; j++) {	//hide image
    	setTimeout("changeOpac(" + j + ",'" + id + "')",(timer * speed));
    	timer++;
    }
  		setTimeout(rotate, millisec);			//change image
    for(j = opacStart; j >= opacEnd; j--) { //show image
    	setTimeout("changeOpac(" + j + ",'" + id + "')",(timer * speed));
    	timer++;
    }
	
}
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}