Deposit system(deposit_submit_success.php)

<?php
session_start();
include('../dbh.php');
$_SESSION['POST'] = $_POST;

    if(isset($_POST['submit'])){
       
        $dep_date  = $_POST['dep_date'];
        $member_id = $_POST['member_id'];
        $member_name = $_POST['member_name'];
        $dep_amount = $_POST['amount'];
        $area         = $_POST['area'];
        $status     = $_POST['status'];
        $getDeposit = "SELECT dep_total FROM user_deposit WHERE member_id = '$member_id' ORDER BY deposit_id DESC LIMIT 1;";
        $result = mysqli_query($conn,$getDeposit);
        $row = mysqli_fetch_assoc($result);
   
        $total_depositAmount = $row['dep_total'] + $dep_amount;
       
        if(    $member_id == ''){
            $_SESSION['dep'] = "<div class='alert alert-danger'>Member id is Required.</div>";
            header("Location:../deposit.php");
            exit();
        }   
       
        if($dep_amount == ''){
            $_SESSION['dep']= "<div class='alert alert-danger'>Deposit Amount is Required.</div>";
            header("Location: ../deposit.php");
            exit();
        }
       
        $sql = "INSERT INTO user_deposit (     date, member_id,member_name,dep_amount,dep_total,area,dep_status)
        values('$dep_date', '$member_id','$member_name','$dep_amount','$total_depositAmount','$area ','$status' );";
        $query = mysqli_query($conn,$sql);
       
       
       
        $_SESSION['dep'] = "<div class='alert alert-success'>Data isnertead.</div>";
        header("Location: ../deposit.php");
}
else{
    $_SESSION['dep'] = "<div class='alert alert-danger'>Data not isnertead.</div>";
    header("Location:../deposit.php");
}
?>