Drawing a path with a line in OpenLayers using JavaScript

Question

I have seen the examples presented here of how to draw a line but the examples only show how to do it with the mouse, by clicking.

What I want to do is draw

Answer 1

I've never done it myself before, but I know OpenSteetMap does it. For example:

http://www.openstreetmap.org/?way=23649627

No idea how difficult it would be to work through their code.