Someone

Shoes.app :title=>'Temperature Converter', :width =>200, :height =>200 do
  def convert(temp, unit='C')
    if unit == "C"
      (temp.to_i * 9.0/5.0) + 32.0
    elsif unit == "F"
      "Fail"
    end
  end
  list_box :items =>["C","F"], :choose =>"C" do |item|
    @unit.text =item.text
  end
  line1 = edit_line :width =>100
  button 'Compute' do
    @result.text = convert(line1.text, @unit.text)
  end
  @unit = para
  @result = para

end