Related table - delete related record question

I have followed the "How To" 'Displaying Relational Tables with Plug-ins'
I am now using a relational table in my own pages

I can get the view (magnifier icon) and update (pencil icon) pages to work for the related records and return to the correct page (shown in the attached jpg file)

However, I can not see how to return to the same page after clicking the delete icon.
I tried setting a session variable - but the delete process seems to destroy it?.

I set the session variable here:

<?php
@session_start();
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$_SESSION["RefNo"] = "".$row_WADAtblnames['miID'] ."";
}
?>

When this did not work, I also set it in the related table html code:
<?php do { $_SESSION["RefNo"] = "".$row_WADAtblnames['miID']; ?>
<tr class="<?php echo($WARRT_AltClass1->getClass(true)); ?>">

Here is my goto action of the delete record behaviour:
tbl_mi_details_detail.php?RefNo=<?php echo $_SESSION['RefNo']; ?>

I also attach a zipped copy of the pages.

Any help would be great.