catch data from javascript using json to make a query in PHP

Question

Hello im using a code from a javascript tutorial wich works great.. its a rating star system, so i can ask my users, your skills on something and they can "answer" using this rating system,....

So i need to "catch" that value.. (using json? or thats what i have been reading here) to finally insert it on the database

Can i store this value on the $_SESSION?.. because that would be great as im using a steps formulary,.... each step storing variables in the session so at the last step i insert all using php in the mysql database.

As you will see the data is ready to bee send :D thats great but , how do i catch it , and store it in the $_SESSION. thanks in advance!!

Also I Asume that i can asign an Id or something to send multiple rates from one page,

this is not specified on the code, and im pretty bad actually with javascript.. (thats why i ask to all the wisdom people on stackoverlflow)

this is the code from the rating system here http://reignwaterdesigns.com/ad/tidbits/rateme/

/*
Author: Addam M. Driver
Date: 10/31/2006
*/

var sMax;   // Isthe maximum number of stars
var holder; // Is the holding pattern for clicked state
var preSet; // Is the PreSet value onces a selection has been made
var rated;

// Rollover for image Stars //
function rating(num){
    sMax = 0;   // Isthe maximum number of stars
    for(n=0; n<num.parentNode.childNodes.length; n++){
        if(num.parentNode.childNodes[n].nodeName == "A"){
            sMax++; 
        }
    }

    if(!rated){
        s = num.id.replace("_", ''); // Get the selected star
        a = 0;
        for(i=1; i<=sMax; i++){     
            if(i<=s){
                document.getElementById("_"+i).className = "on";
                document.getElementById("rateStatus").innerHTML = num.title;    
                holder = a+1;
                a++;
            }else{
                document.getElementById("_"+i).className = "";
            }
        }
    }
}

// For when you roll out of the the whole thing //
function off(me){
    if(!rated){
        if(!preSet){    
            for(i=1; i<=sMax; i++){     
                document.getElementById("_"+i).className = "";
                document.getElementById("rateStatus").innerHTML = me.parentNode.title;
            }
        }else{
            rating(preSet);
            document.getElementById("rateStatus").innerHTML = document.getElementById("ratingSaved").innerHTML;
        }
    }
}

// When you actually rate something //
function rateIt(me){
    if(!rated){
        document.getElementById("rateStatus").innerHTML = document.getElementById("ratingSaved").innerHTML + " :: "+me.title;
        preSet = me;
        rated=1;
        sendRate(me);
        rating(me);
    }
}

// Send the rating information somewhere using Ajax or something like that.
function sendRate(sel){
    alert("Your rating was: "+sel.title);
}

Answer 1

Replace the alert in the sendRate() function with an ajax call to a php script. To do so you will need to use an ajax library, such as jQuery, to POST the value to your server. (see http://api.jquery.com/jQuery.post/)

Example:

$.post('/path/to/php', {rating: sel.title}, function (data) {
    alert('Saved, server responded with' + data);
});