function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		bt_apropos_over = newImage("images/bt_apropos_over.gif");
		bt_nospapiers_over = newImage("images/bt_nospapiers_over.gif");
		bt_distributeurs_over = newImage("images/bt_distributeurs_over.gif");
		bt_environnement_over = newImage("images/bt_environnement_over.gif");
		bt_lexique_over = newImage("images/bt_lexique_over.gif");
		bt_olfaprint_over = newImage("images/bt_olfaprint_over.gif");
		bt_details01_over = newImage("images/bt_details01_over.gif");
		bt_details02_over = newImage("images/bt_details02_over.gif");
		bt_details03_over = newImage("images/bt_details03_over.gif");
		bt_details04_over = newImage("images/bt_details04_over.gif");
    preloadFlag = true;
	}
}