Yes, I included the GetBoolean method on the code behind file.
The problem was that I included it on the code behind for the
Genre.aspx instead of the code behind for the Reviews.aspx page.
Both look so similar that somehow I got them mixed up.
The error is gone. I checked both files but it never occurred to
me that I entered the code on the wrong file. What a silly
mistake. Nevertheless, thanks again for your insight.
Have a great day,