func FetchRecords(user_name: String, password: String) -> Int {
        let pubData = CKContainer.default().publicCloudDatabase
        let predicate = NSPredicate(format: "Username = %@", user_name)
        let query = CKQuery(recordType: "Teachers", predicate: predicate)
        let operation = CKQueryOperation(query: query)
        var Pwd = String()
        var count = Int()
        operation.recordFetchedBlock = { (record : CKRecord!)  in
            let Pwd: String = record["Password"] as! String
            if Pwd == password{
                count=1
            }else{
                count=0
            }
        }
        operation.queryCompletionBlock = { cursor, error in
        }

        CKContainer.default().publicCloudDatabase.add(operation)
       return count
    }