pptp vpn connection in SL6

[M.R.Hadian]

Hi
i am a new comer to scientific linux though i have some experiences with 
ubnuntu and fedora.
i installed SL6 (x86-64 ) on my pc and selected pptp package to be 
installed during system installation. i need pptp connection to be 
connected to internet. in fedora and ubuntu i can create this connection 
from network-manager applet. in SL6 the tab related to vpn connection is 
disable. probably i should install network-manager-pptp but i can not 
using yum to download and install the required packages since i still do 
not have connection to internet with this system. what is the required 
packages and from where i can download them manually?
Best Wishes,
Hadian