I don’t know if it is still Ajax if there is no XML involved.  I used PHP to
parse the CSV data from Yahoo Finance and exported it into JSON.  My server did
not support the json_decode and json_encode functions so I had to manually parse it
to JSON.  The thing I really thought was cool about using JSON is it skips a
whole step.  I did not have to parse XML into stuff I can use in JavaScript. 
All I had to do was have var arr = JSON_data and we can just call arr.index_of_value
to get the actual value.  JSON is pretty cool.