Mongoose don't save new document

I want to save a mongodb document in my node server by mongoose :

mongoose.connect('mongodb://localhost/appJobs');
var db = mongoose.connection;
db.on('error', function() {console.log("error")});
db.once('open', function () {
console.log("connected!");
// init the schema 
var jobSchema = mongoose.Schema({ bName: String , phone :Number ,location:[{longitude:Number,latitude:Number}],Email:String,field:String,exp:String});
var job = mongoose.model('jobs',jobSchema);

And my job data should come from that POST request :

app.get('/postJob', function(req,res){
    console.log("request method :" + req.method);
    // Website you wish to allow to connect
    res.setHeader('Access-Control-Allow-Origin', 'http://127.0.0.1:8020');

    // Request methods you wish to allow
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

    // Request headers you wish to allow
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

    // Set to true if you need the website to include cookies in the requests sent
    // to the API (e.g. in case you use sessions)
    res.setHeader('Access-Control-Allow-Credentials', true);
    res.setHeader('Content-Type', 'application/json');
    // Pass to next layer 

    console.log("Data :");
    var postObject = url.parse(req.url,true).query;
    //testing
    console.log(postObject);
    console.log(postObject.bname);

    // creating and saving the posted job data to mongodb\jobs

    var recJob = new job ({'bName':postObject.bname , 'phone' : postObject.bPhone ,'Email':postObject.bEmail ,'field':postObject.fieldSelected});
        recJob.save(function(error,prod) {
    if(error) {
    console.log("error");
            }
    else {
        console.log("a job was saved to mongodb");

        }
});
    res.send("OK!");


});

The error i get is : "ReferenceError: job is not defined " although i defined at befor the server started . the postObject is the source of the data i want to add .