问从PHP获取变量到javascript (在PHP变量更改后回显不更新)

EN

if(isset($_POST["campaign_id"])){
// Get variables and sanetize
$campaign_id = preg_replace('#[^0-9]#i', '', $campaign_id);

// Create planet list
$planet_list = array();
$sql = "SELECT planet_nr, size, moon FROM planets WHERE campaign_id = $campaign_id";
if ($result = mysqli_query($db_conx, $sql)) {
    /* fetch associative array */
    while ($row = mysqli_fetch_assoc($result)) {
        array_push($planet_list, array($row["planet_nr"],$row["size"],$row["moon"]));
    }
    /* free result set */
    mysqli_free_result($result);
}

// Create region list
$region_list = array();
$sql = "SELECT planet_id, region_id, region_type, owner FROM regions WHERE campaign_id = $campaign_id";
if ($result = mysqli_query($db_conx, $sql)) {
    /* fetch associative array */
    while ($row = mysqli_fetch_assoc($result)) {
        array_push($region_list, array($row["planet_id"],$row["region_id"],$row["region_type"],$row["owner"]));
    }
    /* free result set */
    mysqli_free_result($result);
}

// Convert array's for use in java
$js_planet_list = json_encode($planet_list);
$js_region_list = json_encode($region_list);

$list = array($planet_list, $region_list);
$list = json_encode($list);
echo $list;
exit();

<?php
echo "var planet_list = ". $js_planet_list . ";\n";
echo "var region_list = ". $js_region_list . ";\n";
?>
var ajax = ajaxObj("POST", "campaign.php?c="+campaign_id);
ajax.onreadystatechange = function() {
    if(ajaxReturn(ajax) == true) {
        if(ajax.responseText == "Fail"){
            alert(ajax.responseText);
        }
    }
}
ajax.send("campaign_id="+campaign_id);