Fade speed on slideshow tutorial

Self- explanatory…all I need to know is how to change the alpha fade in and out speed on the photo slideshow tutorial. Can’t find it for the life of me…

delay = 5000;
//-----------------------
function loadXML(loaded) {
	if (loaded) {
		xmlNode = this.firstChild;
		image = [];
		description = [];
		total = xmlNode.childNodes.length;
		for (i=0; i<total; i++) {
			image* = xmlNode.childNodes*.childNodes[0].firstChild.nodeValue;
			description* = xmlNode.childNodes*.childNodes[1].firstChild.nodeValue;
		}
		firstImage();
	} else {
		content = "file not loaded!";
	}
}
xmlData = new XML();
xmlData.ignoreWhite = true;
xmlData.onLoad = loadXML;
xmlData.load("images/images.xml");
/////////////////////////////////////
listen = new Object();
listen.onKeyDown = function() {
	if (Key.getCode() == Key.LEFT) {
		prevImage();
	} else if (Key.getCode() == Key.RIGHT) {
		nextImage();
	}
};
p = 0;
this.onEnterFrame = function() {
	filesize = picture.getBytesTotal();
	loaded = picture.getBytesLoaded();
	preloader._visible = true;
	if (loaded != filesize) {
		preloader.preload_bar._xscale = 100*loaded/filesize;
	} else {
		preloader._visible = false;
		if (picture._alpha<100) {
			picture._alpha += 10;
		}
	}
};
function nextImage() {
	if (p<(total-1)) {
		p++;
		if (loaded == filesize) {
			picture._alpha = 0;
			picture.loadMovie(image[p],1);
			desc_txt.text = description[p];
			picture_num();
			slideshow();
		}
	}
}
function prevImage() {
	if (p>0) {
		p--;
		picture._alpha = 0;
		picture.loadMovie(image[p], 1);
		desc_txt.text = description[p];
		picture_num();
	}
}
function firstImage() {
	if (loaded == filesize) {
		picture._alpha = 0;
		picture.loadMovie(image[0], 1);
		desc_txt.text = description[0];
		picture_num();
		slideshow();
	}
}
function picture_num() {
	current_pos = p+1;
	pos_txt.text = current_pos+" / "+total;
}
function slideshow() {
	myInterval = setInterval(pause_slideshow, delay);
	function pause_slideshow() {
		clearInterval(myInterval);
		if (p == (total-1)) {
			p = 0;
			firstImage();
		} else {
			nextImage();
		}
	}
}