so your original where clause was:
WHERE OrderID = colname
the tutorial is telling you to change that to:
WHERE OrderID = colname AND orders.OrderUserID = paramUserID
and then add a new variable as:
Name paramUserID
Type: integer
Default Value: -1
Runtime Value $_SESSION['UserID']
in your recordset, you have the colname variable as that refences the OrderID URL variable, the tutorial example uses the variable name WADAOrderID instead.