从PHP调用MongoDB脚本

I have mongodb script like below

function getSalaryByTitle(){
 var db = connect('TestMongoDB');
 var titles = db.titles.find({},{emp_no:1, title:1});
 var titles_detail = titles.next();
 var salaries = db.salaries.find({emp_no:{ $in: titles_detail } });
 var jsonArr = [];
 while (salaries.hasNext()){
   var salary_detail = salaries.next();
   var title = titles.next();
   jsonArr.push({
      title: title['title'],
      salary: salary_detail['salary']
  }); 
 }
 return jsonArr;
}

how can I call it from php? Can anyone help me with this?

Thanks in advance..