function show_div(div_id) {
	if(document.getElementById(div_id).style.display == 'block') {
		hide_div(div_id);
	} else {
		document.getElementById(div_id).style.display = 'block';
	}
	
	function hide_div(div_id) {
		document.getElementById(div_id).style.display = 'none';
	}
}