Analyze JavaScript File And Explain How Function Works

OK, So I have a fiddler and javascript file the file have a function I would like to re create in C# I need someone who Is really good in Javascript and you should read the javascript file and explain to me how a function works, So I can re create the same in C# The Javascript is attached I need to know how "anxlv" Works. I have a fiddler you can see in action how it works as well.