function affSubMenu(menu,subMenu) {
	
	var subElements = new Array('sub_festivals','sub_artists','sub_pratique','sub_professionals','sub_magazine','sub_media','sub_community','sub_tickets','sub_members');
	var menuElements = new Array('menu_festivals','menu_artists','menu_pratique','menu_professionals','menu_magazine','menu_media','menu_community','menu_tickets','menu_members');
	
	//All sub_menu not displayed
	for (i=0;i<subElements.length;i++)
	{
		document.getElementById(subElements[i]).style.display='none';
	} 
	
	//Display wanted sub menu
	document.getElementById(subMenu).style.display='block';
	
	//All menu elements get menu background color
	for (i=0;i<menuElements.length;i++)
	{
		document.getElementById(menuElements[i]).style.backgroundColor='';
	}
	//Selected menu element get same color as sub menu
	document.getElementById(menu).style.backgroundColor=getComputedStyle(document.getElementById(subMenu), null).backgroundColor;
}