I have created a new attribute for customers. Whenever customer will do an order at the event when he clicks on the 'Place Order' button, I'm saving some value for this attribute.
But when I try to retrieve that attribute value in admin panel, it's `NULL`. Even the attribute is not showing when I try to get all attributes of that customer. How to resolve this? I want to access that attribute value in admin panel.

My `Observer.php` contains following code snippet to save that attribute.

    $customer = Mage::getSingleton('customer/session')->getCustomer();
    $newAdminIds = 4;
    $customer->setSubAdminIds($newAdminIds)->save();

And the admin panel when I try to retrieve it.
  

    $collection = Mage::getResourceModel('customer/customer_collection')
                ->addNameToSelect()
                ->addAttributeToSelect('email')
                ->addAttributeToSelect('created_at')
                ->addAttributeToSelect('group_id')
                ->addAttributeToSelect('sub_admin_id')
                ->addAttributeToFilter('sub_admin_ids', array('notnull' => true));

Above collection returns empty.