bring out an some size window when click a link in an ajax

i want to ask you how to make an ajax call to bring out an some size
window when click a link.Just tell me the outline instead of detail
about how to.Thank you!

I use an unobtrusive approach, with this prototype library:
http://livepipe.net/projects/control_modal/ .

1. Put a normal link in your view <a class="someclass"
href="some_action">link</a>.
2. Then in the application.js just initialize it:

  $$('a.someclass').each(function(link){
    new Control.Modal(link,{
            [...]
        });
  });

Thank you.I will try it.

An wrote:

I use an unobtrusive approach, with this prototype library:
http://livepipe.net/projects/control_modal/ .

1. Put a normal link in your view <a class="someclass"
href="some_action">link</a>.
2. Then in the application.js just initialize it:

  $$('a.someclass').each(function(link){
    new Control.Modal(link,{
            [...]
        });
  });

hello:
I have downloaded the file "control.modal.2.2.3.js" and put it in
"public\javascripts" directory. Then in the application.js initialize
it:
  $$('a.someclass').each(function(link){
    new Control.Modal(link,{
        opacity: 0.8,
        position: 'relative',
        width: 300,
        height: 50
        });
  });

I have an action named "more" and its view "more.rhtml".In my product
view,there is a link:<a class="someclass" href="more">link</a>.
But when i click the link,this link behaviors like a normal link,not
Pop-up a window.How do i manage it?

Dont' know if still usefull.

If it behaves like a normal link there is an error in javascript or in
loading the javascript file.
Use a tool like firebug for firefox to check if everything is ok.