warn user if all checkboxes are unchecked

Question

I have a form with a series of checkboxes. I want to warn the user, after they hit submit, if ALL of the checkboxes are unchecked. I\'m using the following code to report all

Answer 1

Working Demo : http://jsfiddle.net/MrkfW/

Try this: using .change api as well so it keep the track :)

API: http://api.jquery.com/change/

$("input[type='checkbox'][id^=leg_rider]").change(function(){
    var a = $("input[type='checkbox'][id^=leg_rider]");
    if(a.length == a.filter(":checked").length){
        alert('all checked');
    } else {
        alert('not all checked');
    }
});