function displaySubMenu(obj){

	var className = obj.firstChild.className;
	var tabClass = className.split('_');
	var numClass = tabClass[2];
	var imgBackground = 'url(typo3conf/ext/keolis_template/res/ariannes/' + numClass + '.gif)';
	var elements = document.getElementsByClassName('sousmenu_li');
	
	for( i = 0 ; i < elements.length ; i++ ){
		elements[i].style.backgroundImage = imgBackground;
	}
	obj.lastChild.style.backgroundImage = imgBackground;
	obj.lastChild.style.display = 'block';
	return true;
}

function hideSubMenu(obj){
	obj.lastChild.style.display = 'none';
}