Autotab - フォーカスを自動的に次へ移動してくれるjQueryプラグイン

<form>
<div><strong>Phone Number:</strong></div>
<input type="text" name="areacode" id="areacode" maxlength="3" size="3" /> -
<input type="text" name="number1" id="number1" maxlength="3" size="3" /> -
<input type="text" name="number2" id="number2" maxlength="4" size="5" />
</form> 

<script type="text/javascript">
$(document).ready(function() {
$('#area_code').autotab({ target: 'number1', format: 'numeric' });
$('#number1').autotab({ target: 'number2', format: 'numeric', previous: 'area_code' });
$('#number2').autotab({ previous: 'number1', format: 'numeric' });
});
</script>