function hideObject(id) {
	if(id) {
		id.style.visibility = "hidden";
		id.style.display = "none";
	}
}

function showObject(id) {
	if(id) {
		id.style.display = "block";
		id.style.visibility = "visible";
	}
}

function isOjectVisible(id) {
	if(id) {
		return (id.style.visibility == "visible");
	}
}

function swapVisibility(id) {
	if (isOjectVisible(id)) {
		hideObject(id);
	} else {
		showObject(id);
	}
}