Replace unicode characters (that may pop up in text that is sometimes pasted by user in input field from weird sources) with appropriate ANSI equivalent.

UnicodeHelper.cs

public static class UnicodeHelper
  {
		public static readonly Dictionary<string, string> CharacterPairs = new Dictionary<string, string>()
                     {
                           {"’", "'"}, // UTF-8: E2 80 99
                           {"‘", "'"}, // UTF-8: E2 80 98
                           {"‚", ","}, // UTF-8: E2 80 9A
                           {"‛", "'"},
                           {"“", "\""}, // UTF-8: E2 80 9C
                           {"”", "\""}, // UTF-8: E2 80 9D
                           {"„", "\""}, // UTF-8: E2 80 9E
                           {"‟", "\""},
                           {"′", "'"},
                           {"″", "\""},
                           {"‴", "\""},
                           {"‵", "'"},
                           {"‶", "\""},
                           {"‷", "\""},
                           {"–", "-"},   // UTF-8: E2 80 93
                           {"‐", "-"},
                           {" ", "-"},
                           {"‒", "-"},
                           {"—", "-"}, // UTF-8: E2 80 94
                           {"―", "-"} // UTF-8: E2 80 95
                     };

		public static string FixCharacters(string text)
		{
			StringBuilder sb = new StringBuilder(text);

			foreach (KeyValuePair<string, string> kvp in CharacterPairs)
			{
				sb.Replace(kvp.Key, kvp.Value);
			}

			return sb.ToString();
		}
	}