function display(id){
	var th_open = 'th_' + id;
	var a_open =  'a_' + id;
	if(document.getElementById(id).style.display == 'none' || !document.getElementById(id).style.display) {
		document.getElementById(id).style.display = 'block';
		document.getElementById(th_open).className = 'th_open';
		document.getElementById(a_open).className = 'a_open';
		
	} else {
		document.getElementById(id).style.display = 'none';
		document.getElementById(th_open).className = '';
		document.getElementById(a_open).className = '';
	}
}