Developing a game for webplayer. Do I need to use javascript?

I’m developing a game that I wish to publish in a site. Do I need to code the scripts in javascript in order for the webplayer to play them?

If I work with c# will I be able to export the game as a web player?

Yes, you can code your game in C# and still build a web player. The language used is irrelevant to the final build platform, since everything is compiled into a executable before being embedded in HTML.