Try this: using System; class Program { static void Main() { while(true) { Console.Write("Enter Employee name or 'Quit' to quit : "); string name = Console.ReadLine(); if (name == "Quit") return; double hoursWorked; double hourlyRate; while(true) { Console.Write("Enter Hours Worked : "); bool isValid = Double.TryParse(Console.ReadLine(), out hoursWorked); if (isValid) break; Console.WriteLine("Not a valid number. Please try again"); } while(true) { Console.Write("Enter Hourly Rate of Pay : "); bool isValid = Double.TryParse(Console.ReadLine(), out hourlyRate); if (isValid) break; Console.WriteLine("Not a valid number. Please try again"); } Console.WriteLine(); double grossPay = CalculateGrossPay(hoursWorked, hourlyRate); Console.WriteLine("Gross pay = {0:C}", grossPay); double stateTax = CalculateStateTax(grossPay); Console.WriteLine("State tax = {0:C}", stateTax); double federalTax = CalculateFederalTax(grossPay); Console.WriteLine("Federal tax = {0:C}", federalTax); double FICATax = CalculateFICATax(grossPay); Console.WriteLine("FICA tax = {0:C}", FICATax); double netPay = CalculateNetPay(grossPay, stateTax, federalTax, FICATax); Console.WriteLine("Net pay = {0:C}", netPay); Console.WriteLine(); } } static double CalculateGrossPay(double hoursWorked, double hourlyRate) { return Math.Round(hoursWorked * hourlyRate, 2); } static double CalculateStateTax(double grossPay) { return Math.Round(grossPay * 0.04, 2); } static double CalculateFederalTax(double grossPay) { return Math.Round(grossPay * 0.23, 2); } static double CalculateFICATax(double grossPay) { return Math.Round(grossPay * 0.14, 2); } static double CalculateNetPay(double grossPay, double stateTax, double federalTax, double FICAtax) { return Math.Round(grossPay - (stateTax + federalTax + FICAtax), 2); } }