ajax跨域获取json

$.getJSON("http://kms.re.intra.citic.com/ekp/kms/multidoc/kms_multidoc_knowledge/kmsMultidocKnowledge.do?method=getPersonalDocCount&jsoncallback=?",function(data){
$("#knowCount").text(data.myDocCount);
if(parseFloat(data.myDocCount)==0){
$("#knowCount").addClass("disable");
}
})

string cb = context.Reque;
context.Response.Write(cb + "(" + json + ")");