function addCommas(nStr)
{
	nStr += '';
	x = nStr.split('.');
	x1 = x[0];
	x2 = x.length > 1 ? '.' + x[1] : '';
	var rgx = /(\d+)(\d{3})/;
	while (rgx.test(x1)) {
		x1 = x1.replace(rgx, '$1' + ',' + '$2');
	}
return x1 + x2;
}

function theTrueCost() {
	var salary = document.getElementById('salary').value;
	var systemtime = document.getElementById('systemtime').value;
	var error = "no";
	if (isNaN(salary)) {
		document.getElementById('salary').value = "30000";
		document.getElementById('cost').innerHTML = "$3,000";
		error = "yes";
		window.alert("Please enter a number");
		document.getElementById('salary').focus();
	}
	if (isNaN(systemtime)) {
		document.getElementById('systemtime').value = "10";
		document.getElementById('cost').innerHTML = "$3,000";
		error = "yes";
		window.alert("Please enter a number");
	}
	if((systemtime < 0) || (systemtime > 100)) {
		document.getElementById('systemtime').value = "10";
		error = "yes";
		window.alert("Please enter a percentage between 1-100");
	}
	var cost = parseInt(salary * (systemtime / 100));
	if(error !== "yes") {
		document.getElementById('cost').innerHTML = "$"+addCommas(cost);
	} else {
		document.getElementById('salary').focus();
	}
}