def set_hidden_field(field_locator, options = {})
      field = locate_field(field_locator, HiddenField)
      field.set(options[:to])
    end
def set_hidden_field(field_locator, options = {})
      field = locate_field(field_locator, HiddenField)
      field.set(options[:to])
    end
Verifies that a hidden field exists on the current page and sets
 the value to that given by the <tt>:to</tt> option.

 Example:
   set_hidden_field 'user_id', :to => 1