function addClass(target, classValue) {
	if (!hasClass(target, classValue))
		if (target.className == "")
			target.className = classValue;
		else
			target.className += " " + classValue;
	return true;
};

function removeClass(target, classValue) {
	var removedClass = target.className;
	var pattern = new RegExp("(^| )" + classValue + "( |$)");
	removedClass = removedClass.replace(pattern, "$1");
	removedClass = removedClass.replace(/ $/, "");
	target.className = removedClass;
	return true;
};

function hasClass(target, classValue) {
	var pattern = new RegExp("(^| )" + classValue + "( |$)");    
	if (target.className.match(pattern))
		return true;
	return false;
};


function expand(id) {
	Elem = document.getElementById(id);
	if (hasClass(Elem, "hidden")) {
		removeClass(Elem, "hidden");
	} else {
		addClass(Elem, "hidden");
	}
};

function showhide(id) {
	if (document.getElementById(id).style.display == 'block') {
		document.getElementById(id).style.display = 'none';
	} else {
		document.getElementById(id).style.display = 'block';
	}
}