How setup the jQuery validator plugin

I'm trying to work with the bassistance jQuery validator plugin without success.

I don't understand how to set a specific input for validation:

<script>
$(document).ready(function(){
    $("#form-id").validate({
        username_id: { required:true },
        password_id: { required:true, minlength:8 },
        confirm_id:  { required:true, minlength:8, equalTo:"#password_id" }
    },
    messages: {
        username_id: "Missing username",
        password_id: {
            required: "Missing password",
            minlength: "Password short (5 chars min required)"
        },
        confirm_id: {
            required: "Missing password",
            minlength: "Password short (5 chars min required)",
            equalTo: "Password mismatch"
        }
    });
});
</script>    
<form id="form-id" etc>
    <input id="username_id" name="data[User][username]">&l开发者_如何学运维t;br>
    <input id="password_id" name="data[User][password]"><br>
    <input id="confirm_id" name="data[User][confirm]"><br>
    <input type="submit" value="Register">
</form>

this validator allways write class='valid' in the input i test? I'm sure the problem is in the object name, because I don't understand if I should set the id or the name attribute to let the plugin work properly.

Every tutorial I've found always use identical names for id and name attribute, so I can't understand where I'm wrong.

I've also the problem my name attribute come from cakephp, so my input form name attribute is like data[User][username] and I don't know how to use it with the plugin.

How can I fix it?

PS: I'm using jquery 1.6.1, I see the examples uses the 1.3.2 but firebug doesn't return any error.

You have to use the name attribute, and because they have the square brackets, you need to quote the names like this:

$("#form-id").validate({
    'data[User][username]': { required:true },
    //same for your other fields
},
messages: {
    'data[User][username]': "Missing username",
});