activity starter "of component" socket

[Torotoz]

Hi,
I'm using AI2 on a windows 8 pc and the browser is chrome.
I'm trying to use the activity starter to play a Youtube video. I did look at the http://appinventor.mit.edu/explore/ai2/activity-starter.html page but I found no answer.
The problem is: how do I fill in the 'of component' socket that I find in any setter block I need except 'activitystarter.action'. What is it for?

Thanks
C.

[Hal Abelson]

I think you are looking at the "any activity starter" components.  These "any" components exist for all components in AI2.  They let you build apps where the particular component is selected
at runtime.    You probably don't want these to activity starter, unless your app has several different activity starters.