getJSON回调函数中json解析的有关问题

getJSON回调函数中json解析的问题
{"detailProjectId":1,"rows":[{"address":null,"checkMarks":null,"companyCheckOpinions":null,"detailProject":{"applyDate":"2","createdDate":null,"departmentOfApplier":"22","developStyle":"2","id":null,"projectAchievement":"2","projectApplyName":"22","projectAttachmentAdd":"dd","projectBasis":"2","projectCharg":"dd","projectClient":"2","projectContent":"2","projectCooperationUnit":"2","projectCooperationWays":"2","projectCostEvaluation":"2","projectField":"dd","projectFoundation":"2","projectItemNo":1,"projectItemNoString":"22","projectItemNuber":null,"projectMarketDevelopment":"2","projectName":"sx","projectPhone":"13016983197","projectPlan":"2","projectPlanSchedule":"2","projectReason":"2","projectTask":"2","projectTechFinalRight":"2","projectTimeEnd":"2015-03-27T20:33:04","projectTimeEndString":null,"projectTimeStart":"2015-03-26T20:32:49","projectTimeStartString":null,"projectTrustee":"2","projectWorkRatio":"2","projectWorkSchedule":"2","stateOfApply":"22","url":"2"},"jxReviewRecordId":null,"participant":null,"projectId":null,"reviewMarks":null,"reviewOpinions":null,"sign":null,"time":null}],"publishedProjectId":0,"total":0}

上面是我得到的json，我想在getJSON的回调函数中用alert把detailProject里的applyDate显示出来，应该怎么写这个回调函数呢
------解决思路----------------------
function(a){alert(a.rows[0].detailProject.applyDate)}