def execute
      result = eval(operation)      
      if outfile
        if result.is_a?(SpreadSheet)
          result.write(outfile)
        else
          puts
          puts "Warning: Result is no spread sheet and not written to file!"
          puts "         To view the result use -p flag" unless print
        end
      end

      if print
        puts
        puts "Operation"
        puts "---------"
        operation.split(';').each { |o| puts o }
        puts
        puts "Result"
        puts "------"
        if result.nil? || result.empty?
          puts result.inspect
        else
          puts result
        end
        puts
      end
    end
def execute
      result = eval(operation)      
      if outfile
        if result.is_a?(SpreadSheet)
          result.write(outfile)
        else
          puts
          puts "Warning: Result is no spread sheet and not written to file!"
          puts "         To view the result use -p flag" unless print
        end
      end

      if print
        puts
        puts "Operation"
        puts "---------"
        operation.split(';').each { |o| puts o }
        puts
        puts "Result"
        puts "------"
        if result.nil? || result.empty?
          puts result.inspect
        else
          puts result
        end
        puts
      end
    end
Executes the operation and writes the result to the outfile