function on_mouse_over(id){
	document.getElementById(id+"_1").className="menu_title_negre";
	document.getElementById(id+"_2").className="menu_text_negre";
}
function on_mouse_out(id){
	document.getElementById(id+"_1").className="menu_title";
	document.getElementById(id+"_2").className="menu_text_gris";
}
function on_mouse_over_submenu(id){
	document.getElementById(id).className="submenu_title_sel_tronja";
}
function on_mouse_out_submenu(id){
	document.getElementById(id).className="submenu_title_sel";
}