Language: PHP

I have a form which asks users for their educational details, course details and technical details. When the form is submitted the page goes to a different page to run processes on the information and save parts to a database. HOWEVER(!) I then need to return the page back to the original page, where having access to the original post information is needed.

I thought it would be simple to copy (by value) the multi-dimensional (md) $_POST array to $_SESSION['post']

session_start(); 
$_SESSION['post'] = $_POST;

However this only appears to place the top level of the array into $_SESSION['post'] not doing anything with the children/sub-arrays.

An abbreviated form of the md $_POST array is as follows:

Array
(
    [formid] => 2
    [edu] => Array
        (
            ['id'] => Array
                (
                    [1] => new_1
                    [2] => new_2
                )

            ['nameOfInstitution'] => Array
                (
                    [1] => 1
                    [2] => 2
                )

            ['qualification'] => Array
                (
                    [1] => blah 
                    [2] => blah
                )

            ['grade'] => Array
                (
                    [1] => blah
                    [2] => blah 
                )

        )

    [vID] => 61
    [Submit] => Save and Continue
)

If I echo $_SESSION['post']['formid'] it writes "2", and if I echo $_SESSION['post']['edu'] it returns "Array". If I check that edu is an array (is_array($_SESSION['post']['edu])) it returns true. If I echo $_SESSION['post']['edu']['id'] it returns array, but when checked (is_array($_SESSION['post']['edu]['id'])) it returns false and I cannot echo out any of the elements.

How do I successfully copy (by value, not by reference) the whole array (including its children) to an new array?