gistfile1.phtml

<?php
echo $this->Form->create('Country', array('action' => 'find'));
echo $this->Form->input('name',array('id' => 'Autocomplete'));
echo $this->Form->submit();
echo $this->Form->end();
?>
<script type="text/javascript">
    $(document).ready(function($){
    $('#Autocomplete').autocomplete({
	source:'<?= $this->Html->url(array("controller" => "countries","action"=> "find")); ?>',
	minLength:1
    });
});
    </script>