function showLevel( _levelId ) {
	var divLevel = document.getElementById('div' + _levelId);
	if ( divLevel.style.display == "none") {
		divLevel.style.display = "block";
		}
	else {
		hideLevel( _levelId);
		}
	}
function hideLevel( _levelId) {
	var divLevel = document.getElementById('div' + _levelId);
	divLevel.style.display = "none";
	}