UCM and jsonp (jQuery)

 Hi all! Has anybody queried UCM from the "outside" using an ajax call? My problem is, that I want to query our ucm server with a jsonp request because I have to query it from another domain. I know that ucm can return json by adding IsJson=1 to the url of the query. But still I get a Javascript error if I use the jQuery function getJson. What I do is the following:
    <script type="text/javascript">
        $(function(){
            var ucmurl = 'http://myucmserver/idcplg';
            ucmurl += "?IdcService=GET_SEARCH_RESULTS&QueryText=xReddotPageID <matches> `8801`&IsJson=1&ResultCount=100000&Auth=Intranet&JSONcallback=?";
            $.getJSON(ucmurl, function (data){