How to detect installation of Big5 (Lite) with JavaScript?

[Big5Lite.AppSpot.com]

Hy, is there any way to detect the installation of Big Five or Big5
Lite with JavaScript in Safari Browser without an error popup?

I want to start webapps from safari browser by the application schema
or redirect to Apples AppStore if Big Five isn't currently installed.
I only have a solution using window.setTimeout that fired 2 seconds
after the schema redirection. This workaround display an error
message.

Is there y better solution in JavaScript to detect a schema or
installed application?

Best regards
Robert