Callback Scripts

I've been using callback scripts heavily to change settings within the shader so that the user won't have to. For some reason I always forget to switch the language to python from hscript! That is the first thing I check when my scripts do nothing.

if hou.pwd().parm("placeChoice").eval() == 1: hou.pwd().hdaModule().makePainty("moss")

In pseudo code:
If the parameter on this node is equal to one, run the "makePainty" function attached to this node and pass the token "moss".