Track click on button (external JS widget) as a goal

Hello experts,

I have integrated a widget from OpenTable on a website (see appendix: example screenshot), which is generated by an external javascript, and whichs provides a “button”. The JS-code looks like this:


<script type="text/javascript" src="https://secure.opentable.de/frontdoor/default.aspx?rid=123456&restref=123456&bgcolor=ffffff&titlecolor=000000&subtitlecolor=000000&btnbgimage=https://secure.opentable.de/frontdoor/img/ot_btn_black.png&otlink=FFFFFF&icon=dark&mode=short&hover=1"></script>

Alternatively, you can use just a simple textlink without the “Booking Table”-button and the more of choices, which looks like this:


<a href="http://www.opentable.de/single.aspx?rid=123456&restref=123456">Tischreservierungen</a>

Now I want to track both as a goal, the click on the Javascript widget button and clicking on the external simple link. The latter is already functioning properly:
Goal is triggered, when visitors
Click on a link to an external website
Where the external website URL contains Pattern opentable

–> But with this goal-configuration a click within the external Javascript widget is not counted.

How can I achieve that the user interaction within the widget will also be detected by the previously defined goal?

Thanks in advance.
CT.

http://forum.piwik.org/file.php?5,file=2151