redirect to another page with the same id of that user?

[Alyana Diao]

my system is savings account system, in which i tried to redirect to another php page with the same user id that i want to manage his/her account yet , when i deposit all of the users have the same fk,

here is my code, hope you help me with this, thank you in advance.

this is the query part;

  <?php
session_start();
include "connect.php";

$id = $_POST['index'];

    $sql = "SELECT * FROM `client_accounts` as ca,`ct_trans` as ct WHERE `ca`.`client_id` = `ct`.`ct_client_id` AND `ct`.`ct_client_id` = '$index';";
$query = $db->query($sql);

$arr;

$msg = [];

if($query-> num_rows > 0){
    while ($row = $query->fetch_assoc()){
        $arr['id'] = $row['ct_client_id'];

    }
    $msg['status'] = true;
    $msg['data'] = $arr;
}else {
    $msg['status'] = false;
    $msg['message'] = "Failed";
}

echo json_encode($msg);

?>

this is the javascript part or the jquery;

   function transaction(i){

$.post("tran.php",{"index":i},function(response){
    var data = JSON.parse(response);

            if(data.status){
                    $("#request").html(data.message);
                    window.location="transaction.php";
                }else{
                    $('#request').text(data.message);

}
})
}

it always says undefined index: index

please help me with this, thank you!

[Alyana Diao]

i've already changed this to $index, sorry for that but it is still undefined index: index :(

$id = $_POST['index'];  

[DougC]

Make it a session variable, $_SESSION[xxxxxx] = "$xxxxxx"; now it will be assesible in all scripts for that users session.

[Dani]

$id = $_POST['index']; will only work if someone filled out a form with an index field and ended up on that page.

$id= $_REQUEST['index']; will work if someone goes to the page with a query-string parameter, such as page.php?index=123