function riddle()
{
	document.getElementById('answer').style.visibility = "collapse";
	document.getElementById('riddle').style.visibility = "visible";
	document.getElementById('title_riddle').style.fontWeight = 'bold';
	document.getElementById('title_answer').style.fontWeight = 'normal';
}
function answer()
{
	document.getElementById('riddle').style.visibility = "collapse";
	document.getElementById('answer').style.visibility = "visible";
	document.getElementById('title_riddle').style.fontWeight = 'normal';
	document.getElementById('title_answer').style.fontWeight = 'bold';
}