LUA Error.

[controlsx2]

My script loads up fine but when it calls the event i get an error

[BrantX]

send your LUA script

[controlsx2]

function corcombat(unit, event, miscunit, misc)
print "Coruppter enterd combat"
Unit:RegisterEvent("cor_HealthCheckA",1000,0)
end

function cor_HealthCheckA(unit, event, miscunit, misc)
if Unit:GetHealthPct() < 20 and Didthat == 0 then
Unit:FullCastSpell(14204)
Didthat = 1
else
end
end

RegisterUnitEvent(150001,1,"corcombat")

here ya go