External Javascript call in Unity WebGL

Hi, I have a project where I need to be able to communicate with a Unity WebGL application from the page it is located in. For example, If I click a button "View Model," the unity should load the corresponding scene or move the player to the model (depending on final implementation).

So that leads me to two questions:

1. Is it possible to call functions in Unity from an external application such as the page the player is rendered on?

2. Is it possible to edit the PlayerPrefs from an external application such as the page the player is rendered on?

I know that it is possible with the WebPlayer, but I didn't see anything in the Manual about it.

Unity 5.1.0f3 (64bit)

Thanks in advance!