function switch_image()
{
	curr = parseInt(document.getElementById('currimg').innerHTML);
	max = parseInt(document.getElementById('maximg').innerHTML);
	var newimg = curr+1;
	if (newimg > max) newimg = 0;

	document.getElementById('photo'+newimg).style.zIndex = 0;
	changeOpac(100,'photo'+newimg);
	
	opacity('photo'+curr,100,0,500);
	setTimeout("document.getElementById('photo"+newimg.toString()+"').style.zIndex = 1;",500);
	document.getElementById('currimg').innerHTML = newimg.toString();
}



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

    //determine the direction for the blending, if start and end are the same nothing happens
    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++;
        }
    }
}
//change the opacity for different browsers
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 + ")";
}