checkbox
several checkbox must be checked in order to enable the submit button
by de Montalembert Jonathan
HTML
<form>
<input class='must-accept' type='checkbox' />
<input class='must-accept' type='checkbox' />
<input type='checkbox' />
<input class='must-accept' type='checkbox' />
<input type='submit' disabled />
</form>
JavaScript
$(':checkbox').on('change',function(){
if(!$('input.must-accept[type=checkbox]:not(:checked)').length)
$(this).closest('form').find('input:submit').prop('disabled', false);
else
$(this).closest('form').find('input:submit').prop('disabled', true);
})