AXURE ISSUE: Trying to create a progress bar that fills up on scroll. [on hold]

I am currently designing a infinite-scroll article setup where the progress bar fills up as you scroll down the article.

My current issues that I am coming across is two fold:

  1. How to reset the status of the progress bar when the user scrolls past a certain point.

  2. How to specify when to have the progress bar stat to fill on scroll as opposed to having it start automatically.

Can't seem to get it to work so any help would be appreciated.

Here is the link to the prototype.

http://s8ct3s.axshare.com/#g=1&p=home

Also have the RP file if needed.

Thanks