function open_div(what) {
var opened_div = document.getElementById(what);

	if (opened_div.style.display == 'none') {
		opened_div.style.display = 'block';
	} else {
		opened_div.style.display = 'none';
	}
}

function toggle_ref(title, what) {
	var table = document.getElementById(what);
	title.style.backgroundColor='transparent';

	if (table.style.display == 'none') {
		table.style.display = 'block';
	} else {
		table.style.display = 'none';
	}
}

function ref_mouseover(title, table) {
	if (document.getElementById(table).style.display == 'none') {
		title.style.backgroundColor = 'transparent';
	} 
}

function ref_mouseout(title, table) {
	if (document.getElementById(table).style.display == 'none') {
		title.style.backgroundColor = 'transparent';
	}
}