validates :x, :presence => true, :numericality => true
validates :y, :presence => true, :numericality => true
validates :width, :presence => true, :numericality => true, :natural_number => true
validates :x, :presence => true, :numericality => true
validates :y, :presence => true, :numericality => true
validates :width, :presence => true, :numericality => true, :natural_number => true