Jack Frost Error

Guys my Jack Frost script wont work.

this my script

attackSkillSlot Jack Frost {
lvl 10
dist 8
maxCastTime 0.1
minCastTime 0
sp > 10
stopWhenHit 1
inLockOnly 1
notInTown 1
monsters
maxUses
}

any idea what's wrong in it?
it work before :(

monsters?