it should work if you invoke it like this:
```
Dajaxice.tncapp.sessions_for_device(this.updateSelect.bind(this), {
            'device_id': this.deviceId,
            'date_from': fromTimestamp,
            'date_to': toTimestamp
        });
```
But `bind` is ECMA Script5 and thus not supported by older browsers: http://kangax.github.io/es5-compat-table/#Function.prototype.bind

Maybe we just leave it like it is.