import poser
import string
import aasubrs
reload(aasubrs)
scn = poser.Scene()
for a in scn.Actors():
    if a.IsLight():
        print "found light ",a.Name()
        a.SetShadow(1)
        a.Set??????????(0.5)
poser.ProcessCommand(1559)
#scn.DrawAll();

In this Python script, as run under Poser 7, what Poser Python function should I call to set the parameter called "Shadow" in a light's parameter box in Poser 7?