Multiple autosuggest fields, filters depending on previous results
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I'm trying to figure out a method to see if it is possible to have one text field value (the result of a mysql query of an autosuggest field) be used as a filter for another mysql query for another autosuggest field. As in first field autosuggests a country, and the second field would autosuggest a city based in that country, reading from the mysql results.

I've been using nodstrum's tutorial for the autosuggester, http://www.nodstrum.com/2007/09/19/autocompleter/, and everything seems to be working, but the only method for multiple fields I can think of is having several "rpc.php" files that have different queries within. 
Any suggestions?