added ModelAdmins to use list display in the admin interface

cash/admin.py

@@ -1,8 +1,22 @@
 from django.contrib import admin
 from cash.models import *
 
-admin.site.register(Account)
-admin.site.register(Product)
+
+class AccountAdmin(admin.ModelAdmin):
+	list_display = ('user', 'card_number', 'credit')
+
+
+class ProductAdmin(admin.ModelAdmin):
+	list_display = ('name', 'category', 'price')
+	list_filter = ['category']
+
+
+class ProductCategoryAdmin(admin.ModelAdmin):
+	list_display = ('name', 'comment')
+
+
+admin.site.register(Account, AccountAdmin)
+admin.site.register(Product, ProductAdmin)
 admin.site.register(ProductBarcode)
-admin.site.register(ProductCategory)
+admin.site.register(ProductCategory, ProductCategoryAdmin)