title: how do you deal with multiple drop down forms that are grayed out with scrapy FormRequest
body: <p>So I'm trying to scrap some car info off of Gasbuddy.com, but I'm having some trouble with the scrapy code. </p>
  
  <p>here is what I have so far, let me know what I'm doing wrong:</p>
  
  <pre><code>from scrapy.spider import BaseSpider
  from scrapy.selector import HtmlXPathSelector
  from scrapy.contrib.loader import XPathItemLoader
  from scrapy.http import Request
  from scrapy.http import FormRequest
  
  class gasBuddy(BaseSpider):
  name = "gasBuddy"
  allowed_domains = ["http://www.gasbuddy.com"]
  start_urls = [
      "http://www.gasbuddy.com/Trip_Calculator.aspx",
  ]
  
  def parse(self, response):
      hxs = HtmlXPathSelector(response)
      #for years in hxs.select('//select[@id="ddlYear"]/option/text()'):
          #print years
      FormRequest(url="http://www.gasbuddy.com/Trip_Calculator.aspx",
                  formdata={'Year': '%s'%("2011")},
                  callback=self.make('2011'))
  
  
  def make (years, self, response):
      #this is where we loop through all of the car makes and send the response to modle
      hxs = HtmlXPathSelector(response)
      for makes in hxs.select('//select[@id="ddlMake"]/option/text()').extract()
          FormRequest(url="http://www.gasbuddy.com/Trip_Calculator.aspx",
                  formdata={'Year': '%s', 'Make': '%s'%(years, makes)},
                  callback=self.model(years, makes))
  
  
  def model (years, makes, self, response):
      #this is where we loop through all of the car modles and get all of the data assoceated with it.
      hxs = HtmlXPathSelector(response)
      for models in hxs.select('//select[@id="ddlModel"]/option/text()')
          FormRequest(url="http://www.gasbuddy.com/Trip_Calculator.aspx",
                  formdata={'Year': '%s', 'Make': '%s', 'Model': '%s'%(years, makes, models)},
                  callback=self.model(years, makes))
  
          print hxs.select('//td[@id="tdCityMpg"]/text()')
  </code></pre>
  
  <p>my basic idea with this code was to select one form field then call a formRequest and have a call back to another function that then continues on the loop till i get to the last one then i start reading the info of every car. but i keep getting a few errors... one being 
  gasbuddy has no attribute 'encoding' (which I have no clue what that is about).
  I'm also not sure if you can pass perimeters to a call back function. </p>
  
  <p>any help would be greatly appreciated. </p>