# MouseEnterWindow

> Mouse entered a window (Editor views only).

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine](/engine/6000.0/script-reference/unityengine.md)
* **Assembly:** UnityEngine.IMGUIModule

```csharp
MouseEnterWindow = 20
```

### Remarks

The user hovered the mouse over a window without any buttons being held down.  This event is sent once, as the mouse enters the window.

Note that this event is only sent in the Editor for [EditorWindow](/engine/6000.0/script-reference/unityeditor/editorwindow.md) windows which have [EditorWindow.wantsMouseEnterLeaveWindow](/engine/6000.0/script-reference/unityeditor/editorwindow/wantsmouseenterleavewindow.md) set to true. Mouse enter or leave window events are never sent in the games.