Why my regex doesn't match : it's the first time i use regex. I used .Net regex tester...all is ok....but in my C# application, IsMatch return false.

Here is my code :

    Regex reg = new Regex(@"^[0 - 9]{ 3}_RE_[0 - 9]{ 4}[0-9]{2}[0-9]{2}_[0 - 9]{2}[0-9]{2}[0-9]{2}.TXT$");

    string fileName = "102_RE_20120102_091013.TXT"
    if (reg.IsMatch(fileName))
    {
           // Code Never go here :(
    }

What is wrong please ? I don't see my mistake :(

Thanks a lot :)
