It doesn't look as though you are using Firefox,IE, or Chrome as a browser which are the only browsers currently supported.
If you do use either of those then open up this page in one of them to see detailed install instructions or just go ahead and click one of the links above.
I'm also looking at getting it to work in Safari as well and will update you when it's available.
This browser appears to be Firefox so to get started click the Install Firefox Plugin link above
This browser appears to be IE so to get started click the Install Internet Explorer Plugin link above
This browser appears to be Google Chrome so to get started click the Install Google Chrome Plugin link above
This browser appears to be Safari
For Safari the install process takes three steps
Download SIMBL and install it.
Exit Safari if you're using it
Next, download GreaseKit. To install it, drag the GreaseKit.bundle file to ~/Library/Application Support/SIMBL/Plugins
note: If you don't have a SIMBL/Plugins folder, just create it, then drop GreaseKit.bundle into it
Now re-open Safari. You should see a GreaseKit entry in the Safari menu bar.
Now you are all set to actually install the Affiliater plugin
Click this link to Install Affiliater