function mpb(id) {
	document.getElementById('mp'+id).style.backgroundImage="url('img/mpb.png')";
	id++;
	document.getElementById('mp'+id).style.backgroundImage="url('img/mpb.png')";
}
function mpa(id) {
	document.getElementById('mp'+id).style.backgroundImage="url('img/mpa.png')";
	id++;
	document.getElementById('mp'+id).style.backgroundImage="url('img/mpa.png')";
}
function go(page) {
	document.location = page+".html";
}