This version uses the standalone events stream, using SMIL to sync it with the audio file.
Events will trigger at 10 seconds, 20 seconds, and 30 seconds.
The audio track is blank, so you won't be hearing anything!

The RealNetworks utility that creates standalone event streams (originally part of RealEncoder 5.x) is here.

Here's the events.txt file contents:

u 00:00:10.0 00:00:20.0 &&info&&info2.html
u 00:00:20.1 00:00:30.0 &&info&&javascript:openNewWindowCalledNewInfo("info3.html")
u 00:00:30.1 00:00:40.0 &&NewInfo&&info4.html