Update building.rb

def exp_tech(ceho)
    technology = current_user.technologies.where(:technology_bonus_type => ceho).first!
    research = current_user.researches.where(technology.id => ceho).first!
    lvl = research.lvl
    if lvl =! 0
      if ceho == "L" || ceho == "E"
        1 - lvl * 0.02
      else
        lvl * 0.02 + 1
      end
    else
      lvl = 1
    end
  end