function setWidth() {
	if (document.getElementById) {
		var mainElement=document.getElementById('main');
		var mainLeft=mainElement.offsetLeft;
		mainElement.style.width=document.getElementById('motsCle').offsetWidth-mainLeft-20+'px'; // 20 = padding du body
		document.getElementById('entete').style.width=document.getElementById('motsCle').offsetWidth-mainLeft-20+'px'; // 20 = padding du body
	}
}
window.onload = function() {
	setWidth();
}
window.onresize = function() {
	setWidth();
}