Check if event is triggered by a human

You can check e.originalEvent: if it’s defined the click is human:

Look at the fiddle http://jsfiddle.net/Uf8Wv/

$('.checkbox').change(function(e){
  if (e.originalEvent !== undefined)
  {
    alert ('human');
  }
});

my example in the fiddle:

<input type="checkbox" id='try' >try
<button id='click'>Click</button>

$("#try").click(function(event) {
    if (event.originalEvent === undefined) {
        alert('not human')
    } else {
        alert(' human');
    }


});

$('#click').click(function(event) {
    $("#try").click();
});