我的不同数字程序不起作用

Question

I'm making a program that will add +1 to a year each time the program checks that it's not a distinct digit, until it is one. I have no idea why it's not working, any help would be appreciated. it was working yesterday when I got home, but today it just doesn't want to work.

        private void yearInput_TextChanged(object sender, EventArgs e) // Year Input Textbox \\
        {

        }

        public bool exception;
        public static int yearInputInt;
        public static strng yearInputString;

        private void yearInputConfirm_Click(object sender, EventArgs e) // Year Input Confirm Button \\
        {
            exception = false;
            yearInputString = yearInput.Text;
            yearInputInt = Int32.Parse(yearInputString);
            if (yearInputString.Length == 2)
            {
                while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1))
                {
                    yearInputInt = yearInputInt + 1;
                    yearInputString = yearInputInt.ToString();
                    if (yearInputString.Length == 3)
                    {
                        while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(2, 1))
                        {
                            yearInputInt = yearInputInt + 1;
                            yearInputString = yearInputInt.ToString();
                        }
                    }
                }
            }

            if (yearInputString.Length == 3)
            {
                while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(2, 1))
                {
                    yearInputInt = yearInputInt + 1;
                    yearInputString = yearInputInt.ToString();
                    if (yearInputString.Length == 4)
                    {
                        while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(3, 1))
                        {
                            yearInputInt = yearInputInt + 1;
                            yearInputString = yearInputInt.ToString();
                        }
                    }
                }
            }

            if (yearInputString.Length == 4)
            {
                while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring (2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(3, 1))
                {
                    yearInputInt = yearInputInt + 1;
                    yearInputString = yearInputInt.ToString();
                    if (yearInputString.Length == 5)
                    {
                        while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(3, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(3, 1) == yearInputString.Substring(4, 1))
                        {
                            yearInputInt = yearInputInt + 1;
                            yearInputString = yearInputInt.ToString();
                        }
                    }
                }
            }

            if (yearInputString.Length == 5)
            {
                while (yearInputString.Substring(0, 1) == yearInputString.Substring(1, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(0, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(2, 1) || yearInputString.Substring(1, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(3, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(3, 1) || yearInputString.Substring(2, 1) == yearInputString.Substring(4, 1) || yearInputString.Substring(3, 1) == yearInputString.Substring(4, 1))
                {
                    yearInputInt = yearInputInt + 1;
                    yearInputString = yearInputInt.ToString();
                }
            }
            label2.Text = yearInputString;
        }

When I compile in Visual Studio, the compiling process just crashes and get the error:

1>------ Build started: Project: distinctDigitsRev, Configuration: Debug Any CPU ------ 
1>H:\profile\desktop\C#\distinctDigitsRevamped\distinctDigitsRev\distinctDigitsR‌​ev\Form1.cs(28,23,28,28): error CS0246: The type or namespace name 'strng' could not be found (are you missing a using directive or an assembly reference?) 
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== – 

Answer 1

On line 8, string is spelled wrong.

 public static strng yearInputString;

---

The line should be:

 public static string yearInputString;

Answer 2

Declaration of the variable yearInputString . Notice that you are missing i from string .