Window.Visible

From Xojo Documentation

Property (As Boolean )
aWindow.Visible = newBooleanValue
or
BooleanValue = aWindow.Visible

Supported for all project types and targets.

Controls the visibility of the window.

Notes

If True, the window will be visible when it is opened. After it is opened, setting Visible to False is equivalent to calling the Hide method. Or, if the window not initially shown, setting Visible to True is equivalent to calling the Show method.