title: Undefined variable in django
body: <p>I am a python newbie. i was trying out a django tutorial and got this error. I have two classes :</p>
  
  <pre><code>class Package(models.Model):
      name = models.CharField(max_length =300)
      version = models.CharField(max_length=300,blank=True)
      home_page = models.URLField(blank=True)
      summary = models.TextField()
      description = models.TextField(blank=True)
      keywords = models.TextField(blank=True)
      categories = models.ManyToManyField(**Category**,related_name="packages") //error line
  
  class Category(models.Model):
      number = models.IntegerField()
      topic = models.ForeignKey(Package,related_name='categories')
      value = models.CharField(max_lenght=100)    
  </code></pre>
  
  <p>It gives me an undefined variable 'Category' error.Can somebody help me to find a solution?</p>