Convert SSID list to JSON/Array

Question

I'm trying to make it possible to choose different SSID's to switch the Wlan you are connected to from Browser.

var sys = require('sys');
var exec = require('child_process').exec;
app.get(prefix + '/wlan', function(req, res){
child = exec("iwlist wlan0 scan | grep ESSID", function(error, stdout, stderr){
                if(error !== null){
                    console.log('Exec error ' + error);
                }
                else {
                    res.send(stdout);
                }
 });
});

This is my code so far to get a SSID list..

The Output is like that:

ESSID:"WLAN-GUEST" ESSID:"WLAN1" ESSID:"WLAN-GUEST" ESSID:"WLAN1" ESSID:"WLAN2"

I have no idea why two ESSID's are listed twice but my main question is, how can I parse this to JSON or how can I access each entry like an array (wlanlist[0])?

Edit: I tried to stdout.replace(" ",", "); and JSON.parse but as it's async it's sent without changes. (Not sure if that would work as sync)

Edit2: Trying to access the data like that:

$(document).ready(function() {
$.get(prefix + '/wlan', function(wlanlist){

    document.getElementById("wlanoptions").options[0] = new Option("Select your WLAN:","");
    document.getElementById("wlanoptions").options[1] = new Option(wlanlist[0],wlanlist[0])
});
}); 

Final Result:

var wlanlistarray = stdout.split("ESSID:"); res.send(wlanlistarray);

In addition:

//extract ssid and remove quotes
                var wlanlist = new Array;
                var step1 = stdout.split("ESSID:");
                for(i = 1; i < step1.length; i++){
                    var arr = new Array;
                    arr = step1[i].split('"');
                    //if exists in array -> continue; else create new entry in wlanlist
                    if(wlanlist.indexOf(arr[1]) === -1){wlanlist.push(arr[1]);}
                    else{continue;} 
                }
                res.send(wlanlist);

Answer 1

This should return an array of SSIDs:

stdout.split("ESSID:")

Now clean up the " and you are all done.