Dangling Volume Pricing window

[adib]

The "Volume Pricing" window remains open even though the main purchase window is still open.

Steps to reproduce

1. Open the built-in web store with a product that has volume pricing.
2. Click the "Volume Pricing Available" button.
3. Close the web store window.

Expected result:

• The Volume Pricing details pop-up window should also close as the main window is closed.

Actual result:

• The Volume Pricing pop-up window remains open.