function controle_contact(nom,email,objet,message,parametre)
{	
	var OAjax;
	if (window.XMLHttpRequest) OAjax = new XMLHttpRequest();
	else if (window.ActiveXObject) OAjax = new ActiveXObject('Microsoft.XMLHTTP'); 
	OAjax.open('POST',"signin.php",true);
	OAjax.onreadystatechange = function()
	{
		if (OAjax.readyState == 4 && OAjax.status==200)
		{
			if (document.getElementById) 
			{					
				 document.getElementById('image_chargement').style.display="none";
	             document.getElementById('msg_action').style.display="block";
				document.getElementById('msg_action').innerHTML=OAjax.responseText;
			}
		}
	}
	OAjax.setRequestHeader('Content-type','application/x-www-form-urlencoded');
OAjax.send('email='+email+'&objet='+objet+'&message='+message+'&nom='+nom+'&parametre='+parametre);
}

function envoi_requete(nom,email,objet,message,parametre)
	{
	   document.getElementById('image_chargement').style.display="block";
	   controle_contact(nom,email,objet,message,parametre);
	}