title: Undefined method `^' for String (NoMethodError)
body: <p>I'm very new to Cucumber/Capybara/Ruby/Selenium and I'm just trying to set a simple field with a value.  I'm finding the field with a special selector and then trying to set it:</p>
  
  <pre><code>Capybara.add_selector(:filter_field) {xpath { |field_name| ".//div[contains(@class,'#{field_name}')]//input" }}
  
  def fill_in_field(field_name, value)
    field = find(:filter_field, field_name)
    field.set(value)
  end
  </code></pre>
  
  <blockquote>
    <p>undefined method `^' for "1":String (NoMethodError)
    ./features/support/ui_interface_react.rb:271:in `fill_in_field'</p>
  </blockquote>
  
  <p>The error occurs on the line <code>field.set(value)</code>.  I know that <em>value</em> is a string and <em>field</em> is a <code>#&lt;Capybara::Node::Element&gt;</code>.  What am I doing wrong?</p>