From Xojo Documentation

Read-Only Property (As Boolean )
BooleanValue = aWebAnimator.ZRotationSupported

New in 2010r4

Supported for all project types and targets.

Returns True if z-axis rotation animation is supported by the browser. If False, then the RotateZ method does nothing.

Sample Code

Call RotateZ if supported by the browser:

If Animator1.ZRotationSupported Then
Animator1.RotateZ(ImageView1, 180, 0.5)
End If