I need your help please, I have a form (html-php) which has 10 separate select list and I've struggling to find a way of validating theses lists so the viewer selects a minimum of 1 item from one of these 10 select lists.
I'm using CS5, would be grateful for your help, thank you.

Cheers

Post your HTML. What have you tried so far?

A JavaScript framework could help make that fairly straightforward. jQuery for example has checkbox and checked selectors.

For example:

jQuery(function($) {
    $(document).on({submit: function(event) {

        if($('#form :checkbox :checked').length < 1) {
            alert('Please select at least one option');
            return false;
        }

    }}, '#form');
});