This timeline starts when the Red box is visible. 

The Unique Element IDof this box is: redbox

When you scroll down to the red box, a a timeline will be triggered The name of the timeline started is: bluetimeline  This waypoints function is setup to run ‘On Scene Load’  for this scene. (Check the 'waypoint' JavaScript function in JavaScript tab).  For this to work, this document loads the following JavaScript libraries in the head of the document. You can edit the contents of the … of your exported .html file by clicking on 'Edit HTML Head' in the Document Inspector.  To see this in action, preview this in a browser, and scroll down.