Stupid question from a newbie

Hi everyone:
I,m using the following code and I have some questions

<div id="comment_<%= comment.id.to_s %>">
<%= link_to_remote( "Show Body",
:update => "comment_#{comment.id.to_s}",
:url => { :action => :show_body,
:id => comment }) %>
</div></td>

what exactly do :update,:url,:id, I mean what is the action they done??

Other question

I want to refresh an image, but the image is not a class of the code,
because Iuse the image tag, I dont know where I have to start for do
that, anyone can give me a tip

Thanks

Guille San wrote:

<div id="comment_<%= comment.id.to_s %>">
<%= link_to_remote( "Show Body",
:update => "comment_#{comment.id.to_s}",
:url => { :action => :show_body,
:id => comment }) %>
</div></td>

The official documentation for link_to_remote explains this probably
better than I could myself:
http://www.railsbrain.com/api/rails-2.3.2/doc/index.html?a=M002467&name=link_to_remote

Basically though, :update is the id of the DOM element to be updated
(<div id="comment_#1">...content...</div>. URL in this case is the
"show_body" action of the current controller with the id of the current
comment.