Seting Things on fire

You know how when you use a spell that has fire damage on an npc it sets the npc on fire? but when you use on something else that should burn say a tree or a pile of wood it doesnt burn?
I am trying to make a spell that will set things on fire, but so far it only works on npcs. HELP.
--Thanks!
-MNPred
I am trying to make a spell that will set things on fire, but so far it only works on npcs. HELP.
SCN AAEverBurnBegin ScriptEffectStartpms effectFireDamageEnd
--Thanks!
-MNPred