title: Using multiple fields in django 1.8
body: <p>I have a class where I declare 20 instances of 2 fields.
  <code>models.py</code></p>
  
  <pre><code>class Genre(models.Model):
    name = models.CharField(max_length=200,default="Rock")
     genre_img = models.ImageField(upload_to="media/",default="1992/08/92")
  
    def __str__(self):
        return self.name
  
  class Genrevids(models.Model):
     genrename = models.ForeignKey(Genre)
     vid_1 = models.CharField(max_length=200,default="Z7JgY9zezj4")
     vid_2 = models.CharField(max_length=300,default="Z7JgY9zezd8")
  
     def __str__(self):
        return self.vid1
  </code></pre>
  
  <p><code>views.py</code></p>
  
  <pre><code>class ItemInline(admin.TabularInline):
  model = Genrevids
  extra = 20
  
  class GenreAdmin(admin.ModelAdmin):
  fieldsets = [
      ('The Genre',               {'fields': ['genre_name']}),
      ('Image', {'fields': ['genre_img']}),
  ]
  inlines = [ItemInline]  
  </code></pre>
  
  <p>What this does is, it allows me to add 20 instances of <code>vid_1</code> and <code>vid_2</code>. I want to know if there is a way of adding 20 instances of <code>vid_1</code> and 10 instances of <code>vid_2</code></p>