I haven't been able to find a similar function so I decided to write one. Because I consider myself less than a "novice" in using Regular Expressions, I'm pretty sure that the RegExp I've used can be greatly improved - any suggestions welcome. _IsValidIP will check the following: - no more than 4 numbers - the four numbers to be between 0-255 - first number can't be 0 - nothing else allowed than digits and "." (white spaces not allowed) I have tested it and I couldn't find any bug