var url = 'http://api.bing.net/json.aspx?AppId='+Bing_appID+'&Version=2.2&Sources=Web&Query='+encodeURIComponent(query)+( (Bing_sites) ? '+(site:'+encodeURIComponent(Bing_sites) : "" )+')&Web.Count='+Bing_page_size+'&Web.Offset='+start+'&JsonType=callback&JsonCallback=showBingResults';
to:
var url = 'http://api.bing.net/json.aspx?AppId='+Bing_appID+'&Version=2.2&Sources=Web&Query='+query+( (Bing_sites) ? '+(site:'+encodeURIComponent(Bing_sites) : "" )+')&Web.Count='+Bing_page_size+'&Web.Offset='+start+'&JsonType=callback&JsonCallback=showBingResults';
That did the job. Is there a revised mxp with this code?