# Script: sprite.layers
**URL:** https://community.aseprite.org/t/script-sprite-layers/7051
**Category:** Help
**Created:** [September 27, 2020, 11:51am UTC](https://community.aseprite.org/t/script-sprite-layers/7051 "2020-09-27T11:51:45Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Olga\_Galvanova](https://community.aseprite.org/u/Olga_Galvanova)
#### Post date: [September 27, 2020, 11:51am UTC](https://community.aseprite.org/t/script-sprite-layers/7051/1 "2020-09-27T11:51:45Z")
i’m trying to make a simple script which would delete all hidden layers, so far i have this:
```
local sprite = app.activeSprite
for i, layer in ipairs(sprite.layers) do
if (not layer.isVisible) then
print(i)
app.activeLayer = sprite.layers[i]
app.command.RemoveLayer()
end
end
```
the issue is following:
- when there’s only one hidden layer, everything is fine - that layer gets deleted
- however with more than one hidden layer i get an error: _[string “internal”]:1: Using a nil ‘Layer’ object_ after the layer **above** the hidden layer gets deleted. and then the script stops because of error.
interestingly _print(i)_ returns correct number - if the hidden layers are for example nr. 1 and 5, those are values i get on screen, but before the script stops it deletes layers nr. 1 and 6 (not 5).
i guess it is because the _sprite.layers_ value and/or index of layers change instantly? if so, how to deal with it?
---
### Author:  [@dacap](https://community.aseprite.org/u/dacap)
#### Post date: [September 27, 2020, 3:29pm UTC](https://community.aseprite.org/t/script-sprite-layers/7051/2 "2020-09-27T15:29:33Z")
Hi @Olga_Galvanova, this is a common problem when we have to remove elements from a collection that is being iterated. In this case the problem is that we cannot go through the `sprite.layers` collection and modify it at the same time.
My recommendation would be to create a table of layers first, and then iterate that table:
```lua
local sprite = app.activeSprite
local layers = {}
for i, layer in ipairs(sprite.layers) do
table.insert(layers, layer)
end
for i, layer in ipairs(layers) do
if not layer.isVisible then
app.activeLayer = layer
app.command.RemoveLayer()
end
end
```
---
### Author:  [@Olga\_Galvanova](https://community.aseprite.org/u/Olga_Galvanova)
#### Post date: [September 27, 2020, 3:32pm UTC](https://community.aseprite.org/t/script-sprite-layers/7051/3 "2020-09-27T15:32:03Z")
i see, thank you very much, david!