What is the point of "(new Image()).src" in an onclick event?

Question

This is the HTML for the main logo in the corner of the IMDb website.

<a onclick="(new Image()).src='/rg/home/navbar/images/b.gif?link=%2F%3Fref_%3Dnv_home';" href="/?ref_=nv_home" id="home_img" class="navbarSprite home" title="Home"></a>

I don't understand the onclick event. What is that doing? It doesn't make sense to me to see image instantiation as an onclick event for an image.

Answer 1

It's a tracking click. Although it is creating an image, the sole purpose is to make an easy external request to the tracking URL to log the click (the image is never displayed on the page). b.gif is not really a GIF file, but a server-side tracking script.