function slideshow(name) {
	this.name = name;
	this.slides = new Array();
	this.add_slide = function(src,alt) {
		var img = new Image();img.src=src;img.alt=alt;
		this.slides[this.slides.length]=img;
	}
	this.flip = function(i) {
		// i is 1 based, not zero based
		var img = document.getElementById(this.name);
		if (img) {
			img.src=this.slides[i-1].src;
			img.alt=this.slides[i-1].alt;
			var label = document.getElementById(this.name+'_alt');
			if (label) {
				label.innerHTML = "<b>"+img.alt+"</b>";
			}
		}
	}
}