function change_continent(continent)
{
	var xml_object = null; 
	
	if (window.XMLHttpRequest) // Firefox 
		xml_object = new XMLHttpRequest(); 
	else if(window.ActiveXObject) // Internet Explorer 
		xml_object = new ActiveXObject("Microsoft.XMLHTTP"); 
	else { // XMLHttpRequest non supporté par le navigateur 
		return ;
	}

	var data = null; 
	data = "continent="+continent;
	
	xml_object.open("POST", "phpxml/change_continent.php", true); 
	xml_object.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); 
	
	// écouter la réponse du script php
	xml_object.onreadystatechange = function() {
		if (xml_object.readyState == 4) {
			get_continent = xml_object.responseText;
			document.getElementById('geographie').innerHTML = get_continent;
		}
	}
	xml_object.send(data);
}

function verification(texte, lien)
{
	if (confirm(texte))
		window.location = lien;
	else return;
}