// SLIDESHOW STUFF
var isBlending = false; // Blend function not currently active (default)
function blendimage(divid, imageid, isBackward, millisec) {
    var speed = Math.round(millisec / 100);
    var timer = 0;
	if (!isBlending) {
		isBlending = true;

		// set the current image as background
	    document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";
    
		// make image transparent
		changeOpac(0, imageid);
    
	    // make new image
		if (isBackward) {
			if (imageNumber > 1) {
				imageNumber--;
			} else {
				imageNumber = imageMax;	
			}
			imageNext = '/academics/music/images/slideshow/slide'+imageNumber+'.jpg';
		} else {
			if (imageNumber < imageMax) {
				imageNumber++;
			} else {
				imageNumber = 1;	
			}
			imageNext = '/academics/music/images/slideshow/slide'+imageNumber+'.jpg';
		}
	    document.getElementById(imageid).src = imageNext;

	    // fade in image
	    for (i = 0; i <= 100; i++) {
			setTimeout("changeOpac(" + i + ",'" + imageid + "')", (timer * speed));
    	    timer++;
		}
		// Prevent clicking on advance before transition is complete
        setTimeout("isBlending = false;", (millisec + 250));
	}
	return false;
} 
	
// 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 + ")";
}