Library Global Text Parameter - Uninitialized Variable

[JGoode]

_reqMVO6 = 0
r6 = LIBRARYGLOBAL ("Custom Model View Options", "pos_1_mvo", p1value)
if r6 then
	if (p1value= px1) then
		pos_1 = p1
	endif

	if (p1value= px2) then
		pos_1 = p2
	endif

	if (p1value= px3) then
		pos_1 = p3
	endif
endif

So here is my bit of script for a library global command. It should work besides the fact it is picking up px1, px2 and px3 as uninitialized variables. I believe this is because they are Text type variables. How can I get this script to work?

my values in my Custom Model View Options are defined as shown below:

px1 = "Room Name"
px2 = "Room Number"
px3 = "Room Area"
values "pos_1_mvo" px1, px2, px3

Thanks!