Fixed input control in balancing mode.

app/models/article_price.rb

@@ -15,6 +15,8 @@ class ArticlePrice < ActiveRecord::Base
 
   belongs_to :article
   has_many :order_articles
+
+  validates_presence_of :price, :tax, :deposit, :unit_quantity
   
   # Custom attribute setter that accepts decimal numbers using localized decimal separator.
   def price=(price)