Ruby on Rails

I'm able to follow the docs and create categorie from the rails console but I'm having trouble working those instructions into my controller I know this is wrong I dunno if I can use category instead of @category for the object The browser returns syntax error for the respond to do |format| line unexpected identifier

  # POST /categories
  # POST /categories.json
  def create
    category = Category.new(category_params)
    parent=Category.find(#{params[:parent_id]})
    category.move_to_child_of(parent)

    respond_to do |format|
      if cat.save
        format.html { redirect_to admin_categories_path, notice: 'Category was successfully created.' }
        format.json { render :show, status: :created, location: @category }
      else
        format.html { render :new }
        format.json { render json: @category.errors, status: :unprocessable_entity }
      end
    end
  end