// JavaScript Document
<!--
//function for stripping all commas from a string
function stripCommas(output) {
	i = output.indexOf(",");
	while (i >= 0) {
		output = output.substring(0, i) + output.substring(i+1, output.length);
		i = output.indexOf(",");
	}
	return output;
}

//function for adding commas to a string (ex 1,000,000)
function addCommas(input) {
	output = "";
	i = 0;
	while (i < input.length) {
		if ((i != 0) && (i%3 == 0)) {
			output = "," + output;
			output = input.charAt(input.length-i-1) + output;
		} else {
			output = input.charAt(input.length-i-1) + output;
		}
		i++;
	}
	return output;
}

//function for ensuring that the calc values are numbers and not empty
function frmValidate(frmCalc) {
	//if a field is empty, fill it with 0
	if (frmCalc.calc1.value == "") { frmCalc.calc1.value = "0"; }
	if (frmCalc.calc2.value == "") { frmCalc.calc2.value = "0"; }
	if (frmCalc.calc3.value == "") { frmCalc.calc3.value = "0"; }
	if (frmCalc.calc4.value == "") { frmCalc.calc4.value = "0"; }

	//return false if any field is not a number, else return true
	if (isNaN(stripCommas(frmCalc.calc1.value))) { return false; }
	if (isNaN(stripCommas(frmCalc.calc2.value))) { return false; }
	if (isNaN(stripCommas(frmCalc.calc3.value))) { return false; }
	if (isNaN(stripCommas(frmCalc.calc4.value))) { return false; }
	return true;
}

//function for performing calulation
function frmCalculate(frmCalc) {

	//if the form validate ok then do calculation
	if (frmValidate(frmCalc)) {
		//get values
		val1 = stripCommas(frmCalc.calc1.value).valueOf();
		val2 = stripCommas(frmCalc.calc2.value).valueOf();
		val3 = stripCommas(frmCalc.calc3.value).valueOf();
		val4 = val2 - val3;
		//do calculation
		frmCalc.calc4.value = addCommas(val4.toString());

		if (val2<=249999) frmCalc.calc5.value =  addCommas(Math.round((val1 * 0.015) + (val4 * 0.01) + 500).toString());
		else if (val2>249999 && val2<=499999) frmCalc.calc5.value =  addCommas(Math.round((val1 * 0.015) + (val4 * 0.01) + 1000).toString());
		else if (val2>499999 && val2<=749999) frmCalc.calc5.value =  addCommas(Math.round((val1 * 0.015) + (val4 * 0.01) + 1500).toString());
		else if (val2>749999 && val2<=899999) frmCalc.calc5.value =  addCommas(Math.round((val1 * 0.015) + (val4 * 0.01) + 2000).toString());
		else if (val2>899999) frmCalc.calc5.value =  addCommas(Math.round((val1 * 0.015) + (val4 * 0.01) + 3000).toString());
		
		

	} else {
		//if the validation failed, notify user
		alert("All fields must be numbers.");
	}
}
// -->