Need help identifying a vacuum line

While I was cleaning out the throttle body a few months back on my 2004 Alero with a 3.4L engine I accidentally broke the vacuum line indicated in the image below. The line had become quite brittle and broke very easily. Since this happened I have not noticed any changes in the vehicle's performance. However, having that broken line bothers me and I would like to repair it.

The trouble is I have no idea what that line is for and, even after scouring through the factory service manual, I still have not been able to identify it. So, any help identifying this vacuum line and where I might find a replacement would be appreciated.


http://img.photobucket.com/albums/v495/megaman590/01.jpg



Here is a zoomed in view:

http://img.photobucket.com/albums/v495/megaman590/02.jpg

It looks like the vacuum line from the upper intake manifold that feeds vacuum to the HVAC system. Used to control the actuators under the dash. Usually hard to tell or trace since it gets bundled into the wiring harness and covered with the plastic protector.