* method viewkeys() not available in python2.6
* instead we iterate now with simple for-loop over queries dict

* now a for loop, where we iterate over the keys of the queries dict
* when a key is found in the form queries, we set it to the form value

* new query: query which contains the wished server script to call
* query can contain 'haltestelle.do' or 'abfahrten.do'
* all other values are rejected and answered with empty array

* creating an sequence of two-element tuples with the queries gotten from the ajax calling instance
* use that sequence of tuples with the urlencode() method to create the encoded string of queries

* we get a request from the ajax function in the javascript
* we parse the queries of the request
* we send a request with the parsed queries to the vvo server
* we get the data from the vvo server
* we send the data to the requesting ajax function