var current_button = "";
var last_button = "";
var sel_button = "";

function IsBrowserOK()
//
//	Geeft waar terug als de browser geschikt is voor javascript
//
	{
	
	return (navigator.appVersion>="3");
	}

function Button (image,imagesrc,width,height,textonmo)
//
//	Dit is de constructor voor de 'class' Button..
//	Deze bevat 3 images.
//
	{
	prefix = docbase + imagesrc;

	this.imageoff 	= new Image (width,height);
	this.imageoff.src = prefix + ".gif";

	this.imagemo 	= new Image (width,height);
	this.imagemo.src 	= prefix + "_mo.gif";

	this.imagesel 	= new Image (width,height);
	this.imagesel.src = prefix + "_sel.gif";

	this.textmo		= new String (textonmo);
	}

function NewButton (image,imagesrc,width,height,textonmo)
//
//	Creeerd een nieuwe Button en plakt deze aan de Button class data
//
	{
	if (!IsBrowserOK()) return;
	Button[image]=new Button(image,imagesrc,width,height,textonmo);
	}


function ButtonClick (buttonID)
//
//	buttonID : naam van de geklikte button (in de lijst)
//
	{
	if (!IsBrowserOK()) return;

	if (sel_button!="")
		{
		document.images[sel_button].src=Button[sel_button].imageoff.src;
		sel_button="";
		}

	current_button=buttonID;
	document.images[current_button].src=Button[current_button].imagesel.src;
	sel_button=current_button;
	}

function ButtonMouseOver (buttonID)
	{
	if (!IsBrowserOK()) return;

	current_button=buttonID;
	if (current_button!=last_button && current_button!=sel_button)
		{
		document.images[current_button].src=Button[current_button].imagemo.src;
		window.status=Button[current_button].textmo;

		if (last_button!="" && current_button!=sel_button)
			{
			document.images[last_button].src=Button[last_button].imageoff.src;
			}

		last_button=current_button;
		}
	}

function ButtonMouseOut ()
	{
	if (!IsBrowserOK()) return;

	if (last_button!="" && last_button!=sel_button)
		{
		document.images[current_button].src=Button[current_button].imageoff.src;
		}

	current_button="";
	last_button="";
	window.status="Document: Done";
	}

function LoadPage (buttonID)
	{
	if (!IsBrowserOK()) return;

	current_button = defaultButton;
	document.images[current_button].src=Button[current_button].imagesel.src;
	sel_button=current_button;
	}