function toggle_folder(folder_id, link_id) {
	if(document.getElementById(folder_id).style.display == 'none'){
		document.getElementById(folder_id).style.display = '';
		document.getElementById(link_id).className = '';
	}else{
		document.getElementById(folder_id).style.display = 'none';
		document.getElementById(link_id).className = 'closed_folder';
	}
}