Event.observe(window, "load", function() {
		if ($('calculate')) $('calculate').observe("click", function() {
			var income = 0;
			$$("#rental-calculator input.income").each(function(el) {
				income += Number($F(el).replace(/[^\d.]/g, ""));
			});
			var rent = Math.round(income / 30);
			$("affordability").value = "£"+number_format(rent);
		});
});