function montre(div){
	document.getElementById('offreP1').style.display = "none";
	document.getElementById('offreP2').style.display = "none";
	document.getElementById('offreP3').style.display = "none";
	document.getElementById('offreP4').style.display = "none";
	document.getElementById('offreP5').style.display = "none";
	document.getElementById(div).style.display = "block";
}