partial refresh help

Hi everybody!!! I want to refresh automatically alements from my web page, but I don´t know what Ihave to do. Here is my view

<h1>Hello world/h1> <%= link_to "My blog", posts_path %> <img src="\guarrada\guarrada/foto.jpg" /> <img src="\guarrada\guarrada/foto2.jpg" />

The img tag are the elements I wanna to refresh

Someone can help me

Thanks a lot!!!!!!!!