CakePHP and AJAX to update Database without page refresh

I'm working with CakePHP 1.3.7 and I'm trying to do the following:

On a given page, the user can click a link (or image, or button, doesn't matter) that passes a parameter which is saved into a database. BUT, all this, without refreshing the page.

I've been doing some research and I believe I need to use AJAX as well to acomplish this. However, I can't find the a good example/explanat开发者_JS百科ion on how to do it.

I think that the idea is to create the link using AJAX, which calls the controller/action that would receive the variable as a parameter and performs the operation to save it in its corresponding field/table of the DB.

Does anyone have a small example of what I want to do? Or maybe point me to some tutorial that explains it... Thanks so much in advance!

EDIT

Well, thank you guys for your replies. THey're not working directly, but I think I'm getting closer to what I want. Here's what i'm doing now:

I have this code in my view:

<div id="prev"><a>click me</a></div>

<div id="message_board"> </div>

I call this JS file:

$(document).ready(function () {

$("#prev").click(function(event) {      
    $.ajax({data:{name:"John",id:"100"}, dataType:"html", success:function (data, textStatus) {$("#message_board").html(data);}, type:"post", url:"\/galleries\/add"});
    return false;
});
});

And my add action in my galleries controller looks like:

function add() {

    $this->autoRender = false;  

    if($this->RequestHandler->isAjax()) {

    echo "<h2>Hello</h2>";
    print_r($this->data);
        $this->layout = 'ajax';

        if(!empty($this->data)) {

    $fields = array('phone' => 8, 'modified' => false);
        $this->User->id = 6;
            $this->User->save($fields, false, array('phone'));

        }
}
}

When clicking on the '#prev' element, I get a response from the add action, I know because the text 'Hello' is printed inside #message_board. And it does this without refreshing the page, which is why I need. My problem is that I can't make the $.ajax() function to send any data, when it gets to the controller the $this->data is empty, so it never goes inside the if that saves the info to the database (right now it's saving just an easy thing, but I will want it to save the data that comes from the view).

Can anyone see what am I doing wrong? How can I send the data to the controller?

CakePHP does not matter, most of the code you would need for this would be at clientside. Implementing AJAX by yourself is a pain in the $, so you really want to use a library; currently the most popular is probably jQuery. There's a bunch of examples on their AJAX page: http://api.jquery.com/jQuery.ajax/

So, assuming you have something like this in the document:

<form id="s">
  <input id="q"/>
  <input type="submit" href="Search!"/>
</form>
<div id="r"/>

you can put this in the JavaScript:

$('#s').submit(function(evt) {
  evt.preventDefault();
  $.ajax({
    url: 'foo.php',
    data: {
        query: $('#q').val()
      },
    success: function(data) {
        $('#r').html(data);
      }
  });
  return false;
});

Then your foo.php only needs to return the fragment HTML that would go into the div#r.

EDIT: I forgot to stop the submit :( Thanks to @Leo for the correction.

EDIT: I can see what your confusion is about. You will not get a data. I haven't worked with CakePHP, but I assume $this->data is what you'd get from $_REQUEST['data']? You don't get that on the server. data is a hash of what is getting submitted; you will directly get the $_REQUEST['name'] and $_REQUEST['id'] (which, I assume, translate into CakePHP as $this->name and $this->id).

You need to add

$('#s').submit(function(evt) {
evt.preventDefault();

To prevent a page refresh, as in Amadans answer just refer to your controller/ action in the url variable

$('#s').submit(function(evt) {
  $.ajax({
    url: '/patients/search/',
    data: {
        query: $('#q').val()
      },
    success: function(data) {
        $('#r').html(data);
      }

In the patients/add controller action make sure you return a valid result ( in json is good )