Need some help with the tracker tool

Hi, I tried out the Keyword and Backlink tracker with my URL.
The domain was verified with the DigitalPoint marketplace [I uploaded a file to the root directory].

While configuring my website, I downloaded the tracker php file and uploaded it to my root directory with the default permissions that cPanel accords. I then posted the link in the box.
I got an error,
"Script URL is invalid (your server returned an unexpected result). Make sure your script is not saved as an HTML document."...

Need some help with the tracker tool

Poster :