hi, for reading a key you can use ReadKey method and a good practice for you're application is to use a switch statement like this: Console.WriteLine("1:Add\\n2:Sub\\n3:Mult:\\n4:Div"); Console.WriteLine(); Console.WriteLine("Press 9 to Exit or Enter to Continue "); ConsoleKeyInfo cki = Console.ReadKey(); switch (cki) { case ConsoleKey.D9: Console.WriteLine("exit"); break; case ConsoleKey.Enter: Console.WriteLine("continue"); break; case ConsoleKey.D1: Console.WriteLine("Add"); break; case ConsoleKey.D2: Console.WriteLine("Sub"); break; case ConsoleKey.D3: Console.WriteLine("Mult"); break; case ConsoleKey.D4: Console.WriteLine("Div"); break; default: break; } Anyway I don't understand why use the ENTER key to continue? have you more option than 1,2,3 and 4 ? :) Cheer's, Alex Manolescu

Try this: public void test() { try { Console.WriteLine("Please enter the variables : "); Int32 valueOne = ConvertLine(Console.ReadLine()); Int32 valueTwo = ConvertLine(Console.ReadLine()); Console.WriteLine("Answer : {0}", valueOne + valueTwo); Console.ReadLine(); } catch (Exception e) { Console.WriteLine("Message : {0}", e.Message); Console.ReadLine(); } } private int ConvertLine(string value) { try { if (String.IsNullOrEmpty(value) == false) { return Convert.ToInt32(value); } Console.Error.WriteLine("Empty field is not supported : default value used 0"); } catch (Exception exception) { Console.Error.WriteLine(String.Format("{0} : default value used 0", exception.Message)); } return 0; }