Well I have a 50000+ row table so I can't load all rows into each page for the user to use autocomplete, so I am trying to use an ajax call via the extraParams parameter but don't know:
1) What format to make the results display in on the page being called via ajax (get-dropdown-results.xml in this case)
2) How to get these results into the dropdown
Here's my current source:
$("input#autocomplete-field").autocomplete(
    "/ajax/get-dropdown-results.xml",{
    delay:0,
    minChars:3,
    matchContains:true,
    matchSubset:false,
    max:100,
    extraParams: {
        q: function () { return escape($("input#autocomplete-field").val()); }
    }
});
I am running firebug so I can see the ajax calls are being made correctly (/ajax/get-dropdown-results.xml?q=whatever-they-typed) but I don't know where to put code to handle the returned text.