How to check if a String contains any letter from a to z? [duplicate]

Possible Duplicate:
C# Regex: Checking for “a-z” and “A-Z”

I could just use the code below:

String hello = "Hello1";
Char[] convertedString = String.ToCharArray();
int errorCounter = 0;
for (int i = 0; i < CreateAccountPage_PasswordBox_Password.Password.Length; i++) {
    if (convertedString[i].Equals('a') || convertedString[i].Equals('A') .....
                            || convertedString[i].Equals('z') || convertedString[i].Equals('Z')) {
        errorCounter++;
    }
}
if(errorCounter > 0) {
    //do something
}

but I suppose it takes too much line for just a simple purpose, I believe there is a way which is much more simple, the way which I have not yet mastered.

What about:

//true if it doesn't contain letters
bool result = hello.Any(x => !char.IsLetter(x));

Replace your for loop by this :

errorCounter = Regex.Matches(yourstring,@"[a-zA-Z]").Count;

Remember to use Regex class, you have to using System.Text.RegularExpressions; in your import