How to uncheck checkboxes when check other one

I have four checkboxes.Initially all are checked.When i click the none checkbox the other checkboxes are unchecked.

html

<label class='checkbox'><input type='checkbox' name='a' class="example"  value='1' checked/>A</label>
<label class='checkbox'><input type='checkbox' name='b' class="example" value='2' class='termcls'checked />B</label>
<label class='checkbox'><input type='checkbox' name='c' class="example" value='3' checked/>C</label>
<label class='checkbox'><input type='checkbox' name='none' onchange="uncheckOthers()" value='0' class='termcls'/>(None)</label>

jquery

 function uncheckOthers()
 {
    $('input.example').not(this).prop('checked', false); 
 }

Please help me