title: Ruby 1.9 - invalid multibyte char (US-ASCII)
body: <p>Im trying to make my rails application (2.3.5) to run on Ruby 1.9, I've this function that make some transformations on a string:</p>
  
  <pre><code>def replace_special_chars(downcase = true)
  if downcase 
    string = self.downcase
  else
    string = self
  end
  string.gsub! /á|ã|à|ä|â/, 'a'
  string.gsub! /é|è|ë|ê/, 'e'
  string.gsub! /í|ì|ï|î/, 'i'
  string.gsub! /ó|õ|ò|ô|ö/, 'o'
  string.gsub! /ú|ù|ü|û/, 'u'
  string.gsub! /ç/, 'c'
  string.gsub! /&amp;/, 'e'
  string.gsub! /\s/, '-'
  string.gsub! /[^a-zA-Z_0-9-]/, ''
  string.gsub! /-(-)+/, '-'
  string
  end
  </code></pre>
  
  <p>But when I try to start the server, I got this error:</p>
  
  <pre><code>&lt;internal:lib/rubygems/custom_require&gt;:29:in `require':   
  /Users/.../lib/nzn_string.rb:11: invalid multibyte char (US-ASCII) (SyntaxError)
  /Users/.../lib/nzn_string.rb:11: invalid multibyte char (US-ASCII) 
  /Users/.../lib/nzn_string.rb:11: syntax error, unexpected $end, expecting keyword_end
  string.gsub! /á|ã|à|ä|â/, 'a'
                  ^
  </code></pre>
  
  <p>from :29:in `require'</p>
  
  <p>What's the right way to do this on ruby 1.9?
  I don't know what im missing here</p>