Help with a simple regular expression

Hello,

I'm new to ASP.net and was wondering if you all could help with a password regular expression that I need to make:

1. must have minimum of 4 characters
2. must not exceed 8 characters (8 characters maximum)
3. must contain letters and numbers

Thanks in advance to anyone that replies.

 

I havent checked this but this is 99% right.
Firstly I return false if the password is the wrong length.
Then I check to see if password matches the regex, note the regex may need a tweak but it basically says that it can contain only numbers and letters.

public bool CheckPassword(String password)
{
  if (password.Length < 4 || password.Length > 8) { return false; }
return Regex.Match("([0-9a-fA-F])")
}

Code (markup):