(This is a few days after this thread/post, but i felt it required a reply).

No where in dingus' post did he say that he blindly trusts the client. What he said was that using javascript to validate the form on the client side is much more efficient then using the equivalent Perl. Having a little box that pops up and says 'your password must be 3 letters long', is much more useful when you don't have to make a round trip to the server to see it. This is definately an issue with very long types of forms, where the prospect of possibly reentering all the data, merely because you forgot to put a space in your address or something equally petty, is a bad one. Not to mention it can save you, the developer, quite a lot of effort when you don't have to worry about returning a customized error doc for every single type of mistake the user could possibly make. If you perform the majority of the validation on the client side, then you can simply display an 'invalid data' error doc to the client, and not have to worry about every case.