jQuery Autocomplete-无效标签（Firebug）/未捕获的SyntaxError（Chrome）

invalid label
[Break On This Error] {\"response\":\"true\",\"message\":[{\"label\"... My Park\",\"value\":\"Thier  Park\"}]}

// jquery.min.js:line 16
Uncaught SyntaxError: Unexpected token :
d.d.extend.globalEvaljquery.min.js:16
d.ajaxSetup.converters.text scriptjquery.min.js:16
bQjquery.min.js:16
vjquery.min.js:16
d.support.ajax.d.ajaxTransport.send.c

<script>
    $(document).ready(function() {    

        $(\"#exer_loc\").autocomplete({
            source: function(req, add){
                $.ajax({
                    url: \'<?php echo base_url(); ?>exercise/loc_autocomplete\',
                    dataType: \'json\',
                    type: \'POST\',
                    data: req,
                    success: function(data){
                        if(data.response ==\'true\'){
                           add(data.message);
                        }
                    }
                });
        },
        minLength: 1,
        select: function(event, ui){
            $(this).end().val(ui.item.value);
            }
        });

     });   
</script>

public function loc_autocomplete()
{

    $search = $this->input->post(\'term\');

    $data[\'response\'] = \'false\';
    $this->db->select(\'*\');
    $this->db->from(\'loc_exercise\');
    $this->db->like(\'locations\', $search);
    $locations = $this->db->get()->result();

    if (count($locations) > 0) {
        $data[\'message\'] = array();

        foreach ($locations as $location) {
            $data[\'message\'][] = array(\'label\' => $location->locations,
                \'item\'  => $location->locations,
                \'value\' => $location->locations );
        }

        $data[\'response\'] = \'true\';
    }
    echo json_encode($data);
}

    <script type=\"text/javascript\" src=\"http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js\"></script>

    <script type=\"text/javascript\" src=\"https://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js\"></script>
    <script>
        $(document).ready(function() {    

            $(\"#exer_loc\").autocomplete({
                source: function(req, add){
etc...

    [Object { label=\"My Place\", item=\"My Place\", value=\"My Place\"}, Object { label=\"Pond Park\", item=\"Pond Park\", value=\"Pond Park\"}, Object { label=\"Rock Park\", item=\"Rock Park\", value=\"Rock Park\"}]

//html
{\"response\":\"true\",\"message\":[{\"label\":\"My Place\",\"item\":\"My Place\",\"value\":\"My Place\"},{\"label\":\"Fresh Pond Park\",\"item\":\"Fresh Pond Park\",\"value\":\"Fresh Pond Park\"},{\"label\":\"Cat Rock Park\",\"item\":\"Cat Rock Park\",\"value\":\"Cat Rock Park\"}]}

console.log(req)

Object { term=\"asd\"}