07class Window_Rate < Window_Base

11 def initialize
12 super(64 , 230 , 250, 64)
13 self.contents = Bitmap.new(width - 32, height - 32)
14 refresh
15 end

19 def refresh
20txt1= $buyper　* 100
21txt2=$sellper * 100
22 self.contents.clear
23 self.contents.font.color = normal_color
24 self.contents.draw_text(0, 0, 50, 32, "価格歩合")
25 self.contents.font.color = text_color(1)
26 self.contents.draw_text(55, 0, 80, 32, "売り#{txt1}%")
27 self.contents.font.color = text_color(2)
28 self.contents.draw_text(140, 0, 80, 32, "買い#{txt2}%")
29end

と、作ったのですが実行時に29行目が文法エラーと出ます。なぜですか？