Displays a message at the top of current popup.
The popup must exists. There can be only one popup window on the screen at any given time. Occasionally, you need to display
a short message while popup still open. The message
method allows you to do just that.
The method will slide an overlay at the top of the current popup.
The second argument msgOptions
is a map
of properties as follows:
To display the message
Call it again to close the message