var interval = 18.0; // delay between rotating images (in seconds)
interval *= 1000;

function changeOpac(opacity, id) { 
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")"; 
}

function opacity(id, opacStart, opacEnd, millisec) {
    var speed = Math.round(millisec / 100);
    var timer = 0;

    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}


function rotateDiv(lastDiv) {
	do {
	var newDiv = Math.floor(Math.random()*8+1);
	} while (newDiv==lastDiv);
	
	opacity("refDiv"+newDiv, 0, 100, 2000);
	opacity("refDiv"+lastDiv, 100, 0, 2000);
	
	setTimeout("rotateDiv("+newDiv+")", interval);
}