[Users] Only create popup if popup isn't already open

[Jason Hochschild]

I am having a hard time getting my code to prevent popups from opening
that are already open.  When I try to set a unique ID and then not
open a popup if that ID popup is open, then I am getting either the
popup is undefined or "Uncaught TypeError: Cannot read property
'style' of undefined" in ext-all-debug.js line 2351.

The code for the whole select control can be found here:
http://jasonho.pastebin.com/ibX4v2kV

Is it because I am trying to create the popups inside the
getfeatureinfo event handler for the WMSGetFeatureInfo Control?