function setVisibility (objectID, state) {
	var object = document.getElementById (objectID);
	object.style.display = state;
}

function toggleVisibility (objectID) {
	var object = document.getElementById (objectID);
	state = object.style.display;
	if (state == 'none')
		object.style.display = 'block';
	else {
	if (state == 'block')
		object.style.display = 'none';
	else object.style.display = 'block';
	}
}