Guide needed, Autocomplete fill other field on selection

Question

I'm trying to create a form that when we select the value on the autocomplete field it will fill another field, autocomplete is working fine but I can't make it fill the second field, can someone guide me a little bit?

Here is my .php

 
// Create database connection 
$db = new mysqli($dbHost, $dbUsername, $dbPassword, $dbName); 
 
// Check connection 

if (isset($_GET['term'])) {
     
   $query = "SELECT * FROM registo_obra WHERE Contrato LIKE '{$_GET['term']}%' LIMIT 25";
    $result = mysqli_query($db, $query);
 
    if (mysqli_num_rows($result) > 0) {
     while ($user = mysqli_fetch_array($result)) {
      $res['label'] = $user['Contrato'];
      $res['cliente'] = $user['cliente'];
   array_push( $return_arr, $res );
     }
    } else {
      $res = array();
    }
    //return json res
    echo json_encode($res),"\n";;
}

Here's my jQuery

<script>
$(function() {
    $("#Editbox1").autocomplete({
        source: "data2.php",
select: function (event, ui) {
    var item = ui.item;
    if(item) {
        $("#wb_Text1").val(item.cliente);
                    
                    }
                }
    });
    });

</script>