# GUI.WindowFunction

> Callback to draw GUI within a window (used with GUI.Window ).

## Definition

* **Type:** Delegate
* **Namespace:** [UnityEngine](/engine/6000.5/script-reference/unityengine.md)
* **Assembly:** UnityEngine.IMGUIModule

```csharp
public delegate void GUI.WindowFunction(int id)
```

## Remarks

This function takes the ID number of the window to be drawn. Its body should contain GUI calls to display the window, much like a standard OnGUI function. This function can then be passed as a parameter to [GUI.Window](/engine/6000.5/script-reference/unityengine/gui/window.md) to draw the appropriate contents.