function show_timetable(){
	var tt = document.getElementById('timetable');
	tt.style.display = 'block';		
	
	if( navigator.appName == "Microsoft Internet Explorer"){
		tt.style.left = '700px';
		tt.style.top = '110px';
	}else{
	}
}

function hide_timetable(){
	var tt = document.getElementById('timetable');
	tt.style.display = 'none';
	
}