function getMonstersInArea(area)
        local monsters = {} 
        for x = area.fromx, area.tox do
                for y = area.fromy, area.toy do
                        for z = area.fromz, area.toz do
                                monsterpos = {x=x,y=y,z=z,stackpos=253}
                                monster = getThingFromPos(monsterpos)
                                if isMonster(monster.uid) == true then
                                        table.insert(monsters, monster.uid)
                                end
                        end
                end
        end
        return monsters
end


function onStepIn(cid, item, position, fromPosition)

if not isPlayer(cid) then return false end

local positions = {
[TILE_ID_1] = {fromx = ..., fromy = ..., fromz = ..., tox = ..., toy = ..., toz = ...},
[TILE_ID_2] = {fromx = ..., fromy = ..., fromz = ..., tox = ..., toy = ..., toz = ...}
}

local monsters = getMonstersInArea(positions[item.itemid])

        if #monsters > 0 then
                for i, #monsters do
                        doRemoveCreature(monsters[i])
                end
        end   
        return true
end