function show_layer(_var,_menu){ //show_layer(nombre_del_submenu,nombre_del_menu)
	var arLayers = new Array('mnu_services','mnu_contacto');
	var arMenus = new Array('service_menu','contactus_menu');

	for(var _x=0;_x < arLayers.length;_x++){
		document.getElementById(arLayers[_x]).style.display='none';
		document.getElementById(arLayers[_x]).style.visibility='hidden';
	}

	for(_x=0;_x < arMenus.length;_x++){
		document.getElementById(arMenus[_x]).style.backgroundPosition='0 0';
	}


	if(_var!=''){
		document.getElementById(_var).style.display='block';
   		document.getElementById(_var).style.visibility='visible';
	}
	if(_menu!=''){
		try{
		document.getElementById(_menu).style.backgroundPosition='0 -38px';
		}catch(err){
			document.getElementById(_menu).style.setProperty('background-position','0 -38px',null);
		}
	}
	
}