Cache static content for asp.net mvc 4

Question

I am trying to configure caching static page elements (images, scripts, styles). file web.config.

<clientCache cacheControlCustom="public;max-age"
             cacheControlMaxAge="1.00:00:00"
             cacheControlMode="UseMaxAge" />

Controller

Response.Cache.SetExpires(DateTime.Now.AddSeconds(30));
Response.Cache.SetCacheability(HttpCacheability.Public);

What is the reason why there is no cached content?