var slides = new Array(4);

slides[1] = "slide1.PNG";
slides[2] = "slide2.PNG";
slides[3] = "slide3.PNG";
slides[4] = "slide4.PNG";

var frame = 1;
var slidesource;
var spantext;
var t = 0;
var hidden = 0;
var playing = 1;

function init() {
t = setInterval("next();", 2000);
slidesource = document.getElementById("slide");
slidesource.src = slides[frame];
}

function previous() {
determinePrevious();
slidesource.src = slides[frame];
}

function determinePrevious() {
if (frame == 1) {
frame = 4;
}
else {
frame = frame - 1;
}
}

function next() {
determineNext();
slidesource.src = slides[frame];
}


function determineNext() {
if (frame == 4) {
frame = 1;
}
else {
frame = frame + 1;
}
}

function togglevis() {
if (hidden == 0) {
document.getElementById("slideshow").style.display="none";
document.getElementById("previous").style.display="none";
document.getElementById("next").style.display="none";
document.getElementById("stop").style.display="none";
document.getElementById("play").style.display="none";
document.getElementById("hide").style.display="none";
document.getElementById("show").style.display="block";
hidden = 1;
}
else {
document.getElementById("slideshow").style.display="inline";
document.getElementById("previous").style.display="inline";
document.getElementById("next").style.display="inline";
document.getElementById("hide").style.display="inline";
document.getElementById("show").style.display="none";
hidden = 0;
if (playing == 1) {
document.getElementById("stop").style.display="inline";
document.getElementById("play").style.display="none";
}
else {
document.getElementById("stop").style.display="none";
document.getElementById("play").style.display="inline";
}
}
}

function stop() {
clearInterval(t);
document.getElementById("stop").style.display="none";
document.getElementById("play").style.display="inline";
playing = 0;
}

function play() {
t = 0;
t = setInterval("next();", 2000);
slidesource = document.getElementById("slide");
slidesource.src = slides[frame];
document.getElementById("stop").style.display="inline";
document.getElementById("play").style.display="none";
playing = 1;
}