# File rbSnack/tkSnackUtil.rb, line 199
    def drawVertLabels 
      return if @labelSteps==nil or @labelSteps.type!=Array or @labelSteps[1]<=0
      step=@labelSteps[1]
      wy=0
      while wy <= @worldFrame[3]
        if @worldFrame[1]<=wy
          y= getY wy
          txt=wy.to_s
          TkcText.new(self,@viewPort[0]-20,y){text txt}   
          TkcLine.new(self,@viewPort[0] ,y,@viewPort[2],y){ fill '#ddf'}
        end
        wy+=step
      end      
    end