function Calc() { 
	amount = $('amount').value;
	down = $('down').value;
	ar = $('interest').value/100;
	term = $('term').value;
	
	rate = ar/12;
	num_payments = term*12;
	p = amount - down;
	
	var total = (Math.floor((p*rate)/(1-Math.pow((1+rate),(-1*num_payments)))*100)/100);
	
	total = total.toString();
	
	var cents = total.substring(total.indexOf('.'), total.length);
	var toSeperate = reverse(total.substring(0, total.indexOf('.')));
	
	var seperated = '';
	for (var i=0; i<toSeperate.length; i++) {
		if (i>0 && i % 3 == 0)
			seperated += ',';
		seperated += toSeperate.charAt(i);
	}
	seperated = reverse(seperated);
	
  var toDisplay = '$' + seperated + cents;
		
	$('monthly_payments').innerHTML = toDisplay;
}

function reverse(toReverse) {
   if (!toReverse) return '';
   var revstr='';
   for (i = toReverse.length-1; i>=0; i--)
       revstr+=toReverse.charAt(i)
   return revstr;
}

function selectAll() {
	var willCheck = $('select_all_boxes').checked;
	var toToggle = document.getElementsByTagName("input");
	for (var i=0; i < toToggle.length; i++) {
		toToggle[i].checked = willCheck;
	}
}

function openFullscreen(url) {
	window.open(url, 'HighDefinitionTour', 'fullscreen=yes,height='+screen.height+',width='+screen.width+',toolbar=no,menubar=no,resizable=no,scrollbars=yes')
}

function openStandard(url) {
	var height = screen.height;
	window.open(url, 'StandardTour', 'height=' + height + ',width=880,toolbar=no,menubar=no,resizable=no,scrollbars=yes')
}