QuickForm validation suggestion

I've been spending a good amount of time looking at the different form validation scripts out there and contemplating porting the one I wrote to PHP. QuickForm seems to a nice combination of features and low code volume requirements. One thing that I think is missing is some validation options, some of which I've written some rules to do, but others might make more sense to be more integrated. If I have missed something please correct me or clue me in. I'd like the validation to be able to check to make sure that not only are response valid, but they are one of the options presented to the user. For example, with a select box, the submitted value, should be one of the items in the select list, like wise radio buttons should only be allowed to be one of the radio values. For the select box, this can easily be accomplished it seems with the following rule: function validateSelect($element, $submittedvalue) { $possiblevalues = $element->getValue() return in_array($value, $possiblevalues) } I'd suggest that something like this be included as one of the rules shipped with QuickForm. But there's doesn't seem to be an easy way to make sure for a group that it's selected value is one of the values of the elements in the group. Can somebody suggest a way to write a rule to do this? Also, if there was a web page detailing what the available rules are, that would super handy. Anyway, I know everyone's busy, but in case people hadn't thought of this stuff, I figured I'd post. As I write rules, I'll try and contribute them and pitch in, in other ways. Thanks, Bryn