The JSON value of the
[up-accept] attribute becomes the overlay's
<a href='/dashboard' up-dismiss>Close</a>
[href] will only be followed when this link is clicked in the root layer.
In an overlay the
click event's default action is prevented.
You can also omit the
[href] attribute to make a link that only works in overlays.
The overlay's dismissal value as a JSON string.
A message the user needs to confirm before the layer is closed.
The close animation's duration in milliseconds.
The close animation's easing function.