var currentpage = 1;
var maxpages = 4;
var intID;


function displayPage(pageid) {
	clearInterval(intID);
	currentpage = pageid;
    for(var $i=1;$i<=maxpages;$i++) {
        document.getElementById('page'+$i).style.display='none';
    }
    document.getElementById('page'+pageid).style.display='';
}

function clearall() {
	document.getElementById('butt1').src="userfiles/image/products-off.jpg";
	document.getElementById('butt2').src="userfiles/image/bureau-off.jpg";
	document.getElementById('butt3').src="userfiles/image/servicessupported_off.jpg";
	document.getElementById('butt4').src="userfiles/image/businessmodels_off.jpg";
}

function showPage() {
	clearall();
	
	if (currentpage == 1) { document.getElementById('butt1').src="userfiles/image/products-on.jpg"; }
	if (currentpage == 2) { document.getElementById('butt2').src="userfiles/image/bureau-on.jpg"; }
    if (currentpage == 3) { document.getElementById('butt3').src="userfiles/image/servicessupported_on.jpg"; }
	if (currentpage == 4) { document.getElementById('butt4').src="userfiles/image/businessmodels_on.jpg"; }
	
	for(var $i=1;$i<=maxpages;$i++) {
        document.getElementById('page'+$i).style.display='none';
    }
    document.getElementById('page'+currentpage).style.display='';
	
	currentpage++;
	
	if (currentpage > maxpages) {
		currentpage = 1;
	}
}
function startButtonChanger() {
	intID = setInterval ("showPage()", 7000);
}