I'm trying to figure out how to implement c# scripting into my game (XNA with C#). I will be using C# as the scripting language.

My question is, how to call functions that take more than 1 frame to finish?

For example:

class UserScript : Script
{
    public override void execute(Game game)
    {
        //script must wait for dialog to be closed
        game.openDialog("This is a dialog");

        //script should'nt wait for this
            int goldToGive = 100;
            goldToGive += 100;
            game.addGold(goldToGive);
        //

        //script should wait for cinematic to end
        game.startCinematic("name_of_cinematic");

        //doesn't wait
        game.addGold(100);
    }
}

I found that you can do that with yield, but I'm not sure if it's the correct way (It's from 2010, the article mentioned no longer exists). http://stackoverflow.com/questions/3540231/implementing-a-simple-xml-based-scripting-language-for-an-xna-game

Is yield the answer? If so, can anyone point me any examples/tutorials/books? I haven't found any regarding my situation.

If not, what approach should I take? or am I better off with multi-threading?