jquery check if all checkbox is not checked

1if (!$("#checkboxID").is(":checked")) {
2    // do something if the checkbox is NOT checked
3}

1<form id="form1" action="/controller/action" method="post">
2   <input type="checkbox" name="box1" class="cBox" />
3   <input type="checkbox" name="box2" class="cBox" />
4   <input type="checkbox" name="box3" class="cBox" />
5  <input type="submit" value="Submit" />
6</form>
7<script>
8$('#form1').submit(function() {
9   if ($('input:checkbox', this).length == $('input:checked', this).length ) {
10            // everything's fine...
11   } else {
12            alert('Please tick all checkboxes!');
13            return false;
14   }
15});
16</script>

1 $('#checkAll').click(function () {    
2     $('input:checkbox').prop('checked', this.checked);    
3 });