How can the values from two Comboboxes be effectively stored in a PHP session for further processing?

To store the values from two Comboboxes in a PHP session, you can retrieve the selected values from the Comboboxes using $_POST, then set them as session variables. This allows you to access and use the selected values across multiple pages within the same session.

```php
<?php
session_start();

if(isset($_POST['combobox1']) && isset($_POST['combobox2'])){
    $_SESSION['selected_value1'] = $_POST['combobox1'];
    $_SESSION['selected_value2'] = $_POST['combobox2'];
}
?>
```

Make sure to replace 'combobox1' and 'combobox2' with the actual names of your Comboboxes.