RT_PCR positive control

[Malathi Hari]

I am trying to work out RT-PCR conditions to detect the expression of a 
small GTPase gene in various tissues and was wondering what positve control
to use.  I think I need to use Glyceraldehyde 3 phosphate dehydrogenase as
 a positve.  I was wondering if someone could point me in the right direction
and tell me where I can obtain primers or primer sequences for a postive 
control.
Thanks in advance.

Malathi