I need to write an essay about this comparing it to a modern equivalent, I used the Movie ''Sword of the Valiant'' the topic needs to be on either on how the changes in the stories reflect the type of audience reading/seeing or How the changes in the stories emphasize different values, and I think the second one would be easier, since both of them are for the same kind of audience, but I'm having some trouble understanding the values in Sir Gawain and the story in general, because the movie is very different from the actual story. If anyone can help me I would appreciate it, and if you have seen the Movie (which I doubt) I would very much appreciate it if you could help me out in these differences, thank you !

What are you comparing to what? Please name the two things you are comparing. (Your post is a bit jumbled.)

Sir Gawain and the Green Knight to Sword of the Valiant, the movie adaptation.

But those two things are the same. Isn't the assignment to compare two individuals like Sir Gawain and the Green Knight to Superman and Lex Luthor or to David and Goliath?

No, although that would be much easier. The assignment is to compare the original classic story, to a modern equivalent of it, like the movie the sword of the valiant. And we need to focus on ''how the changes in the stories emphasize different values'' I know it's a bit confusing, I mean you'd think since it's the SAME story it has the same values, it confuses me a lot, but the stories are very different, I just need a bit more of insight to Sir Gawain and the Green knight, because I have read the story, and researched it, but the vales and themes in it still confuse me, I doubt anyone can fully help me with this unless they've seen "sword of the valiant'' which I doubt anyone has because it is an old movie, and not a good one at that.

Well, there's lots about the movie on imdb.com and also in Wikipedia. Maybe those two will help.

As to the print version, there's this --

http://www.sparknotes.com/lit/gawain/

Just don't plagiarize.