function file theme url

How can I direct this to look in my twenty ten child theme directory instead of the plugin directory?

plugins_url( 'my_jsfile.js', __FILE__) , array('jquery') );

I tried content_url then added the path but I need to include the theme name, I’d rather it use the directory the child theme css is in, but I had problems with that before cause it kept picking up the twenty ten css instead.