I have created a function that I hope will validate an IP address sent to it. I have searched the site for one but I wasn't able to find one that was bullet-proof from all the ones I have run up against here. This one will not only validate that the values are in the right range, but will also tell you what Class the IP address falls under. It will check for the invalid number ranges, 0.xx.xx.xx or 127.xx.xx.xx for example, as well as for the reserved ranges above 239.xxx. I've seen a lot of att