[R] p-value gee

[Web de]

Hi to all,
I found in the R-help archive how to calculate the p-value for a gee result:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/74150.html

but there are two questions (I am afraid they are basic questions ...)
1. why is the result multiplicated  with 2
2. how could I decide between lower.tail =TRUE and FALSE:
example:
2*pnorm(c(1.8691945,0.5882351,2.4903091,1.9287802,2.3172983,2.2092593,2.2625959,1.6395695), 
lower.tail =TRUE)  

I did not find anything about lower tail in my books only about one 
tailed and two tailed.

With regards
Carmen