python - Adding a new record in Django Admin gives persistent error -

i'm starting mess around django. created new project , new app. in app created model , activated admin. seemed work fine. wanted add couple new records database using admin. in first 3 tables went fine, in fourth 1 (called 'locations') error saying: 'tuple' object has no attribute 'encode'. full error here on pastebin: http://pastebin.com/wjzat6nn

the strange thing when go general admin page , want click table on got error, error (so without trying add anything).

my question: why happening? maybe there wrong models.py, pasted below message well.

all tips welcome!

from django.db import models  # create models here. class countries(models.model):     country = models.charfield(max_length=100)     def __unicode__(self):         return self.country  class organisationtypes(models.model):     organisationtype = models.charfield(max_length=100)     def __unicode__(self):         return self.organisationtype  class organisations(models.model):     organisationname = models.charfield(max_length=200)     organisationtype = models.foreignkey(organisationtypes)     countryoforigin = models.foreignkey(countries)     def __unicode__(self):         return self.organisationname  class locations(models.model):     organisation = models.foreignkey(organisations)     countryoflocation = models.foreignkey(countries)     telnr = models.charfield(max_length=15)     address = models.charfield(max_length=100)     def __unicode__(self):         return self.organisation, self.countryoflocation, self.telnr, self.address 

here:

def __unicode__(self):         return self.organisation, self.countryoflocation, self.telnr, self.address 

you're returning tuple. expects single string.

change this:

def __unicode__(self):         return "%s - %s - %s - %s" % (self.organisation self.countryoflocation, self.telnr, self.address)