function CalculateROI()	{
	
	var sale = $('sale').value;  // required
	var comm = $('comm').value;  // required
	var split = $('split').value;  // required

	var missing = '';
	var numtodo = 0;
	
	if (sale.length == 0) {
		numtodo = numtodo + 1;
		missing = missing + '  (' + numtodo + ') Sale Price \n ';
	}
	if (comm.length == 0) {
		numtodo = numtodo + 1;
		missing = missing + '  (' + numtodo + ') Commission \n ';
	}
	if (split.length == 0) {
		numtodo = numtodo + 1;
		missing = missing + '  (' + numtodo + ') Split \n ';
	}
	missing = 'There are ' + numtodo + ' required item(s) missing: \n ' + missing;
	if (numtodo > 0) {
		alert(missing);
		return;
	}
	
	sale = sale.replace("$", "");
	sale = sale.replace(/,/g, "");
	
	var commpercent = comm.indexOf("%");
	if (commpercent > 0) {
		comm = comm.replace("%", "");
		comm = comm/100;
	}
	if (comm > 1) {
		comm = comm/100;
	}
	if (comm < .001) {
		comm = comm * 100;
	}
	
	var splitpercent = split.indexOf("%");
	if (splitpercent > 0) {
		split = split.replace("%", "");
		split = split/100;
	}
	if (split > 1) {
		split = split/100;
	}
	if (split < .01) {
		split = split * 100;
	}
	
	var ROI = 0;
	ROI = 4 * (sale * split * 0.5 * comm) - 2247;
	var newROI = formatCurrency(ROI);
	var oROIanswer = $('ROIanswer');
	oROIanswer.value = newROI;
	
}

function formatCurrency(num) {
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num)) num = "0";
	sign = (num == (num = Math.abs(num)));
	num = Math.floor(num*100+0.50000000001);
	cents = num%100;
	num = Math.floor(num/100).toString();
	if(cents<10)
	cents = "0" + cents;
	for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
		num = num.substring(0,num.length-(4*i+3))+','+num.substring(num.length-(4*i+3));
	return (((sign)?'':'-') + '$' + num + '.' + cents);
}