C# How to tell if DVD drive tray is open?

I have a DVD reading and burning app in C#. I want to be able to detect the difference between an empty drive (no disk) and an open drive.

Edit: After some more googling, I think a better problem description is "I want to access the drive tray status - open or closed"

I can use

ManagementObjectSearcher("SELECT * FROM Win32_LogicalDisk WHERE DriveType= 5")

to find all the dvd drives in the system, and the properties tell me if there is a disk in the drive. Access property tells me if there is a blank disk.

But Access is null when the drive is open, and when the drive is shut and empty. And I don't see any other property that changes when the drive opens or closes.

Anyone know a way to distinguish an open drive from a closed and empty drive?

I am using Win7, but ideally the solution would work on XP and Vista also.