Vmware virtual network creation using scripts

Hi,

I am trying to create a script for Opennebula network creation for vcenter. When I try the following script then i get error:

NAME = “#{service_name}-frontend”
PHYDEV = 99
VN_MAD = vcenter
NETWORK_ADDRESS = 192.168.150.0
NETWORK_MASK = 255.255.255.0
GATEWAY = 192.168.150.1

How do we give the parameters like distributed switch and distributed port group etc?