if flow statement

getazure.rb

@@ -1,7 +1,7 @@
 require 'rubygems'
 require 'open-uri'
-require 'Nokogiri'
-require 'FileUtils'
+require 'nokogiri'
+require 'fileutils'
 
 FileUtils.mkdir_p 'downloads/'
 FileUtils.cd 'downloads/'
@@ -9,9 +9,9 @@ xml = Nokogiri::XML(open('http://s.ch9.ms/Shows/Azure-Friday/feed/mp4high'))
 item = xml.xpath('//item')
 
 item.each do |s|
-
+next if File.exist? s.at('enclosure')['url'].to_s.split('/').last
 File.open("#{s.at('enclosure')['url'].to_s.split('/').last}", "wb") do |file|
 			puts " downloading " + s.at('enclosure')['url'].to_s.split('/').last
 				file.write open("#{s.at('enclosure')['url']}").read
 			end
-end
+end