checking input for morse code converter

[newbill]

I want to check the input from the user to make sure that they only enter dots and dashes and any other letters or numbers will give back and error message. Also i wanted to allow the user to enter a space yet when i am converting how can i remove or ignore the white space?\[code\]string permutations; string entered = ""; do { Console.WriteLine("Enter Morse Code: \n"); permutations = Console.ReadLine(); . . } while(entered.Length != 0);\[/code\]Thanks!