[horde] imp display mode variable?

[Rick Romero]

Hey guys - I feel a bit ashamed for asking this, but I'm having a  
problem finding what I'm looking for...

I have a custom login form for multiple webmail systems, and I store a  
cookie in the postauthenticate hook that 'remembers' the last webmail  
option chosen.  Some of my users aren't so keen on the new dynamic  
Horde, but I want it to be default, so I added the select dropdown to  
my login menu.

What variable stores that choice, and would be available to the  
postauthenticate hook?  I thought maybe something in the $browser  
object, but I'm not sure how to extrapolate the data it contains..

Help :)

Thanks,
Rick