# on-size parameter (skin)

Source: https://ref.dm-lang.org/skin/param/on-size
Added in BYOND 482.

### Applies to
> [All](https://ref.dm-lang.org/skin/control/index.md)

### Format
> `string`

[Command](https://ref.dm-lang.org/skin/commands/index.md) executed when this control is resized. If you are dragging a window edge or splitter, the command won't run until you finish.

No command will be sent in response to size or splitter changes made by [winset()](https://ref.dm-lang.org/proc/winset.md).

If you include `[[*]]` in the command, it will be replaced by the control's new size. Likewise, `[[width]]` will be replaced with the width and `[[height]]` with the height. (See [embedded winget](https://ref.dm-lang.org/skin/commands/embed.md) for more details on the `[[...]]` format.)

### See also
> [size parameter](https://ref.dm-lang.org/skin/param/size.md)