still not working

inter.js

var app = require('app')
var assert = require('assert')
var db  = app.db;


var get_state = function(cb) {
    
    db.get('_state', function(err,doc) {
        
        if(err) {
            console.log("processed_seq does not exist");
            cb(null,0);
        }
        else {
            var seq = doc.processed_seq;

            console.log("processed sequence = "+seq);
            if(seq)
                cb(null,seq);
            else
                cb(new Error("uups"), 0);
        }
    });
}

var set_state = function(seq, cb) {
    
    db.get('_state', function(err,doc) {
        
        if(err) {
            console.log("processed_seq does not exist");
            db.save('_state',{processed_seq:seq},function(e,res){console.log(e.message + " saved new state");});
            cb(null,seq);
        }
        else {
            var rev = doc._rev;
            db.save('_state',rev,{processed_seq:seq},function(e,res){console.log("saved state");});
            console.log("saved state@" + rev + " = "+ seq);
            cb(null,seq);

        }
    });
}

// retrieve changes
var act_on_changes = function() {

    get_state(function(e,seq) {
    
        console.log("get state = " + seq);
        db.changes({since: seq, filter: 'documents/all'}).on('response',function(res) {
            res.on('data',function(change) {
                console.log("changes:");
                console.log(change);
                console.log("save_seq = " + seq);
                newseq = Math.max(change.seq,seq);
                
        
                // persist procecced changes
                set_state(newseq, function(e,s) {
                    console.log("saved seq = " + s);
                });
    
            });
            res.on('end', function() {
                console.log("oops, connection closed");
            });
        });

    });
};

// loop
act_on_changes();