app2.php
has this one:
<input name="cpID" type="hidden" value="<?php echo $_POST['cpID']; ?>">
which pass the id to app3.php which works fine!
app3.php has these which displays everything fine.
<input name="total_dir" type="hidden" value="<?php echo $_POST['total_dir']; ?>">
<input name="total_sh" type="hidden" value="<?php echo $_POST['total_sh']; ?>">
<input name="cpID" type="hidden" value="<?php echo $_POST['cpID']; ?>">
the two new hidden fields are only entered on app2.php and passed to app3.php and work on app3.php.
but from app3.php - app4.php these are no longer displayed and are present in the form.