that should be on two lines

like this :

set morphs for head to 0

import  poser
scn = poser.Scene()
fig = scn.CurrentFigure()
act = fig.Actor("Head")
parms = act.Parameters()
if parms:
    for parm in parms:
        if parm.IsMorphTarget() :
            parm.SetValue(0)
 print "Done"

my mistake, sorry  the if starts the line then the next lines are indented as shown.