if(!MooTools) {
	alert("Requires Mootools!");
} else {
	$("calcbtn").addEvent("click", function() {
		$("calc").set('send', {
			'onRequest' : function() {
				$("calcbtn").disabled = true;
			},
			'onSuccess' : function(responseText, responseXML) {
				$('calc_results').empty();
				$('calc_results').set('html', responseText);
				$("calcbtn").disabled = false;
			}
		});
		$("calc").send();
	});
}