image_catalogue_1	=	new Image();
image_catalogue_2	=	new Image();

/* on les pre-charge */
image_catalogue_1.src="images/contour_produit.png"; 
image_catalogue_2.src="images/contour_produit_roll.png";

function invertionImage(id_image, etat) {

	if(document.getElementById(id_image)) {
		if (etat == 'true') {
			document.getElementById(id_image).src	= image_catalogue_2.src;
		} else {
			document.getElementById(id_image).src	= image_catalogue_1.src;
		}
	}
}