need help with adsense-delux

Hello everyone,
I’m here to ask some help with adsense deluxe.

I have activated the adsense deluxe plugin in my WPblog and have followed the instructions from the home page Adsense-Delux WordPress Plugin.

“…..its simplicity was great and it offered some of the control I thought I wanted while avoiding template changes. Phil’s plugin is configured by pasting your AdSense code into the plugin PHP file, then adding an HTML comment (“<!–adsense–>”) anywhere in a post, then your ads are substituted for the placeholder when the post is served. The plugin operates in the common role of a WordPress filter hook.”

“After installation (described later and in the plugin distribution’s readme file) click on the WordPress Admin “Options” link, then select “Adsense” on the sub menu to get to the settings interface. Copy your AdSense code from Google and paste it into the form on the Options page and give it a name. If it’s the style you’ll use most often, just name it “default”. Now you can edit an existing post in your WordPress blog by adding either <!–adsense–> to use whatever you select as your default AdSense format, or by referencing the name you defined, such as <!–adsense#default–>. Now view your post after saving the changes. You should see AdSense ads wherever you inserted the HTML comment.”

When I checked it out, I got the following message

“Cannot load adsense-deluxe.php.”

It has not worked for me. I’m not sure what I do wrong or what have overlooked.
If someone wants to give me some help with (small steps) instructions I would greatly appreciate it.
Thank you
Steve