jQuery启用按钮（如果已选中所有复选框）并将CSS添加到禁用按钮

Question

I am trying to enable a button if all checkboxes are selected and disable it if any are unselected. I have achived this by using this code:

checkBoxes.change(function() {
    submitButton.attr("disabled", checkBoxes.is(":not(:checked)"));
 });

What I am not sure about is how to add and remove a css class if the button is enabled or disabled.

Example here: jsfiddle

Any help would greatly be appreciated.

Answer 1

Posting my comment as an answer now...

var checkBoxes = $('input.compulsory'),
    submitButton = $('#continue');

checkBoxes.change(function () {
    submitButton.attr("disabled", checkBoxes.is(":not(:checked)"));
    if(checkBoxes.is(":not(:checked)")) {
        submitButton.addClass('disabled');
    } else {
        submitButton.removeClass('disabled');
    }       
});

DEMO HERE