function controle(champ,fin_tempo)
{
	if(champ != '' && document.getElementById(champ).value != '')
	{
		var chaine = '';
			
		chaine = "champ=" + champ + "&valeur=" + encodeURI(document.getElementById(champ).value);
	
		if(chaine != '')
		{
			
			chaine += "&time=" + (new Date()).getTime();
			
			
			if(window.XMLHttpRequest) ajax = new XMLHttpRequest(); else if(window.ActiveXObject) ajax = new ActiveXObject("Microsoft.XMLHTTP"); 
			ajax.open("POST", "http://www.charte-graphique.net/controles/contact.php", true);
			ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
			ajax.send(chaine);	
			
			ajax.onreadystatechange= function()		
			{
				if (ajax.readyState == 4)
				{
					if (ajax.status == 200)
					{
						if(ajax.responseText != '-1')
						{
							document.getElementById(champ).style.backgroundColor='#FDE9E9';
							document.getElementById('erreur_'+champ).innerHTML = ajax.responseText;
						}
						else
						{
							document.getElementById(champ).style.backgroundColor='';
							document.getElementById('erreur_'+champ).innerHTML = '';	
						}
					}
				}
			}	
		}
	}
	else
	{
		document.getElementById(champ).style.backgroundColor='';
		document.getElementById('erreur_'+champ).innerHTML = '';	
	}
}