function position(e) {
	var posx, posy;
	if (!e)
		var e = window.event; 
	if (e.pageX || e.pageY) {
		posx = e.pageX;
		posy = e.pageY;
	}
	else if (e.clientX || e.clientY) {
		var scrollx = (document.body.scrollLeft) ? document.body.scrollLeft : document.documentElement.scrollLeft;
		var scrolly = (document.body.scrollTop) ? document.body.scrollTop : document.documentElement.scrollTop;
		posx = e.clientX + scrollx;
		posy = e.clientY + scrolly;
	}
	var tab = new Array(posx, posy);
	return tab;
}

function montre(texte, event) {
	var espacementx = 10;
	var espacementy = 10;
	var tab = position(event);
	x = tab[0]+espacementx;
	y = tab[1]+espacementy;
	var txt = document.createTextNode(texte);
	var div = document.getElementById('div_ville');
	div.appendChild(txt);
	div.style.left = x+'px';
	div.style.top = y+'px';
	div.style.display = 'block';
}

function cache() {
	var div = document.getElementById('div_ville');
	div.style.display = 'none';
	div.removeChild(div.firstChild);
}