Supplier Invoice

hi, i made the revision but still can't edit invoice. any suggestion?

supplier_invoice.php

//page(_($help_context = "Enter Supplier Invoice"), false, false, "", $js);
if (isset($_GET['ModifySI'])) {
//display_notification_centered(_("Modify SI TRUE<br>"));
    $help_context = "Modifying Supplier Invoice";
    $error_msg = '';

    if (isset($_GET["trans_no"])) {
        $trans_no = $_GET["trans_no"];
    }
    elseif (isset($_POST["trans_no"])) {
        $trans_no = $_POST["trans_no"];
    }
    else    $trans_no = null;

    if ($trans_no != null) {
        $_SESSION['page_title'] = sprintf(_("Modifying Supplier Invoice # %d."), $trans_no);
        if (is_closed_trans(ST_SUPPINVOICE, $trans_no)) {
            $error_msg = _("The selected transaction was closed for edition.");
        }
        else {
            $void_entry = get_voided_entry(ST_SUPPINVOICE, $trans_no);
            if ($void_entry != null) {
                $error_msg = _("The selected transaction has already been voided.");
            }
            else {
                $result = get_gl_trans(ST_SUPPINVOICE, $trans_no);
                if (db_num_rows($result) == 0) {
                    $error_msg = _("Cannot find Supplier Invoice # ") . $trans_no;
                }
            }
        }
    }
    else {
        $_SESSION['page_title'] = _("Modifying Supplier Invoice (with missing #).");
        $error_msg = _("Supplier Invoice # is missing!");
    }

    if ($error_msg == '') {
        $supp_trans = new supp_trans(ST_SUPPINVOICE);
        read_supp_invoice($trans_no, ST_SUPPINVOICE, $supp_trans);
        page($_SESSION['page_title'], false, false,'', $js);
        $_SESSION['supp_trans'] = $supp_trans;
        $_SESSION['inv_modify'] = true;
        $_SESSION['old_trans'] = $trans_no;
        $_SESSION['old_date'] = $supp_trans->tran_date;
    }
    else {
        $_SESSION['inv_modify'] = false;
        $_SESSION['old_trans'] = null;
        $_SESSION['old_date'] = null;
        page($_SESSION['page_title'], false, false,'', $js);
        display_error($error_msg);
        end_page(true);
        exit;
    }
}
elseif (isset($_GET['New'])) {
//display_notification_centered(_("New TRUE, Modify SI FALSE<br>"));
    $_SESSION['inv_modify'] = false;
    $_SESSION['old_trans'] = null;
    $_SESSION['old_date'] = null;
    page(_($help_context = "Enter Supplier Invoice"), false, false, "", $js);
}
else {
//display_notification_centered(_("Modify SI unchanged...<br>"));
    page(_($help_context = "Enter Supplier Invoice"), false, false, "", $js);
}
//----------------------------------------------------------------------------------------

check_db_has_suppliers(_("There are no suppliers defined in the system."));

//---------------------------------------------------------------------------------------------------------------

if (isset($_GET['AddedID']))
{
    $invoice_no = $_GET['AddedID'];
    $trans_type = ST_SUPPINVOICE;

    echo "<center>";
    display_notification_centered(_("Supplier invoice has been processed."));
    display_note(get_trans_view_str($trans_type, $invoice_no, _("View this Invoice")));

    display_note(get_gl_view_str($trans_type, $invoice_no, _("View the GL Journal Entries for this Invoice")), 1);

    hyperlink_no_params("$path_to_root/purchasing/supplier_payment.php", _("Entry supplier &payment for this invoice"));

    hyperlink_params($_SERVER['PHP_SELF'], _("Enter Another Invoice"), "New=1");

    hyperlink_params("$path_to_root/admin/attachments.php", _("Add an Attachment"), "filterType=$trans_type&trans_no=$invoice_no");
   
    display_footer_exit();
}

//--------------------------------------------------------------------------------------------------

if (isset($_GET['New']))
{
    if (isset( $_SESSION['supp_trans']))
    {
        unset ($_SESSION['supp_trans']->grn_items);
        unset ($_SESSION['supp_trans']->gl_codes);
        unset ($_SESSION['supp_trans']);
    }

    $_SESSION['supp_trans'] = new supp_trans(ST_SUPPINVOICE);
}

//--------------------------------------------------------------------------------------------------
function clear_fields()
{
    global $Ajax;
   
    unset($_POST['gl_code']);
    unset($_POST['dimension_id']);
    unset($_POST['dimension2_id']);
    unset($_POST['amount']);
    unset($_POST['memo_']);
    unset($_POST['AddGLCodeToTrans']);
    $Ajax->activate('gl_items');
    set_focus('gl_code');
}

function reset_tax_input()
{
    global $Ajax;

    unset($_POST['mantax']);
    $Ajax->activate('inv_tot');
}

//------------------------------------------------------------------------------------------------
//    GL postings are often entered in the same form to two accounts
//  so fileds are cleared only on user demand.
//
if (isset($_POST['ClearFields']))
{
    clear_fields();
}

if (isset($_POST['AddGLCodeToTrans'])){

    $Ajax->activate('gl_items');
    $input_error = false;

    $result = get_gl_account_info($_POST['gl_code']);
    if (db_num_rows($result) == 0)
    {
        display_error(_("The account code entered is not a valid code, this line cannot be added to the transaction."));
        set_focus('gl_code');
        $input_error = true;
    }
    else
    {
        $myrow = db_fetch_row($result);
        $gl_act_name = $myrow[1];
        if (!check_num('amount'))
        {
            display_error(_("The amount entered is not numeric. This line cannot be added to the transaction."));
            set_focus('amount');
            $input_error = true;
        }
    }

    if (!is_tax_gl_unique(get_post('gl_code'))) {
           display_error(_("Cannot post to GL account used by more than one tax type."));
        set_focus('gl_code');
           $input_error = true;
    }

    if ($input_error == false)
    {
        $_SESSION['supp_trans']->add_gl_codes_to_trans($_POST['gl_code'], $gl_act_name,
            $_POST['dimension_id'], $_POST['dimension2_id'],
            input_num('amount'), $_POST['memo_']);
        reset_tax_input();
        set_focus('gl_code');
    }
}

//------------------------------------------------------------------------------------------------

function check_data()
{
    global $Refs;

    if (!$_SESSION['supp_trans']->is_valid_trans_to_post())
    {
        display_error(_("The invoice cannot be processed because the there are no items or values on the invoice.  Invoices are expected to have a charge."));
        return false;
    }

    if (!$Refs->is_valid($_SESSION['supp_trans']->reference))
    {
        display_error(_("You must enter an invoice reference."));
        set_focus('reference');
        return false;
    }

    if (!is_new_reference($_SESSION['supp_trans']->reference, ST_SUPPINVOICE))
    {
        display_error(_("The entered reference is already in use."));
        set_focus('reference');
        return false;
    }

    if (!$Refs->is_valid($_SESSION['supp_trans']->supp_reference))
    {
        display_error(_("You must enter a supplier's invoice reference."));
        set_focus('supp_reference');
        return false;
    }

    if (!is_date( $_SESSION['supp_trans']->tran_date))
    {
        display_error(_("The invoice as entered cannot be processed because the invoice date is in an incorrect format."));
        set_focus('trans_date');
        return false;
    }
    elseif (!is_date_in_fiscalyear($_SESSION['supp_trans']->tran_date))
    {
        display_error(_("The entered date is not in fiscal year."));
        set_focus('trans_date');
        return false;
    }
    if (!is_date( $_SESSION['supp_trans']->due_date))
    {
        display_error(_("The invoice as entered cannot be processed because the due date is in an incorrect format."));
        set_focus('due_date');
        return false;
    }

    if (is_reference_already_there($_SESSION['supp_trans']->supplier_id, $_POST['supp_reference']))
    {     /*Transaction reference already entered */
        display_error(_("This invoice number has already been entered. It cannot be entered again.") . " (" . $_POST['supp_reference'] . ")");
        return false;
    }

    return true;
}

function handle_void_invoice()
{

    if (!exists_supp_trans(ST_SUPPINVOICE, $_SESSION['old_trans']))
        return false;
    if (!post_void_supp_trans(ST_SUPPINVOICE, $_SESSION['old_trans']))
        return false;

    $ret = void_transaction(ST_SUPPINVOICE, $_SESSION['old_trans'], $_SESSION['old_date'], 'Invoice Modification - Old Version');

    if ($ret)
    {
        display_notification_centered(_("Old invoice has been voided."));
    }
    else {
        display_error(_("Old invoice cannot be voided."));
        set_focus('trans_no');
    }
    return $ret;
}
//--------------------------------------------------------------------------------------------------

function handle_commit_invoice()
{
    copy_to_trans($_SESSION['supp_trans']);

    if (!check_data())
        return;

    $invoice_no = add_supp_invoice($_SESSION['supp_trans']);

    $_SESSION['supp_trans']->clear_items();
    unset($_SESSION['supp_trans']);

    meta_forward($_SERVER['PHP_SELF'], "AddedID=$invoice_no");
}

//--------------------------------------------------------------------------------------------------

if (isset($_POST['PostInvoice']))
{
//    handle_commit_invoice();
    if ($_SESSION['inv_modify']) {
            if (handle_void_invoice($_SESSION['old_trans'], $_SESSION['old_date'])) {
                display_notification_centered(_("New invoice data:<br>") . print_r($_SESSION['supp_trans'], TRUE) . "<br>");
                handle_commit_invoice();
            }
        }
        else {
            handle_commit_invoice();
        }
}

journal_inquiry.php

//    "/sales/customer_credit_invoice.php?ModifyCredit=%d"
//     12=> Customer Payment,
   ST_CUSTDELIVERY => "/sales/customer_delivery.php?ModifyDelivery=%d",
//   16=> Location Transfer,
//   17=> Inventory Adjustment,
//   20=> Supplier Invoice,
ST_SUPPINVOICE => "/purchasing/supplier_invoice.php?ModifySI=Yes&trans_no=%d",
//   21=> Supplier Credit Note,