// Global variables
var isCSS, isW3C, isIE4, isNN4, isImages, objArray;

// initialize upon load to let all browsers establish content objects
function initDHTMLAPI() {
	if (document.images) {
		isImages = true;
		isCSS = (document.body && document.body.style) ? true : false;
		isW3C = (isCSS && document.getElementById) ? true : false;
		isIE4 = (isCSS && document.all) ? true : false;
		isNN4 = (document.layers) ? true : false;
		isIE6CSS = (document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? true : false;
	} else {
		isImages = false;
	}
}

// Convert object name string or object reference
// into a valid element object reference
function getRawObject(obj) {
	var theObj;
	if (typeof obj == "string") {
		if (isW3C) {
			theObj = document.getElementById(obj);
		} else if (isIE4) {
			theObj = document.all(obj);
		} else if (isNN4) {
			theObj = seekLayer(document, obj);
		}
	} else {
		// pass through object reference
		theObj = obj;
	}
	return theObj;
}

// Convert object name string or object reference
// into a valid style (or NN4 layer) reference
function getObject(obj) {
	var theObj = getRawObject(obj);
	if (theObj && isCSS) {
		theObj = theObj.style;
	}
	return theObj;
}

// Set the visibility of an object to visible
function show(obj) {
	var theObj;
	theObj = getObject(obj);

	if (theObj) {
		theObj.display = "block";
	}
}

// Set the visibility of an object to hidden
function hide(obj) {
	var theObj;
	theObj = getObject(obj);

	if (theObj) {
		theObj.display = "none";
	}
}

var vizObj;

function next(obj) {
	hide(vizObj);
	show(obj);
	vizObj = obj;
}

function previous(obj) {
	hide(vizObj);
	show(obj);
	vizObj = obj;
}

window.onload = function () {
	vizObj = "pic01";
	initDHTMLAPI(); 
}