function createRequestObject() {
	var xhr = null;
	if (window.XMLHttpRequest) {	// Mozilla, Firefox, Safari, ...
		xhr = new XMLHttpRequest();
		if (xhr.overrideMimeType) {
			xhr.overrideMimeType('text/xml');
		}
	} else if (window.ActiveXObject) {	// Internet Explorer
		try {
			xhr = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			xhr = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	else {	// XMLHttpRequest non supporté par le navigateur
		alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest (AJAX)...");
		xhr = false;
	}
	return xhr;
}

function videContent(text) {
	if (text == "votre adresse mail")
		document.getElementById('newsletter_mail').value = "";
}

function rempliContent(text) {
	if (text == "")
		document.getElementById('newsletter_mail').value = "votre adresse mail";
}

function inscriptionNewsletter(mail) {
	var http_ajax = createRequestObject();
	http_ajax.onreadystatechange = function() {
		if (http_ajax.readyState == 4)
			if (http_ajax.status == 200) {
				document.getElementById('header_newsletter').innerHTML = http_ajax.responseText;
			} else {
				document.getElementById('header_newsletter').innerHTML = "";
			}
	}
	http_ajax.open('GET', 'inscriptionNewsletter.php?m='+mail, true);
	http_ajax.send(null);
}