检索表单数据Node.js

Question

玉文件：

form(method="post", action="/upload", enctype="multipart/form-data")
      input(type="file", name="logName")
      input#promptNumErrors(type="number", name="numErr", placeholder="Number of Errors")
      button(type="submit") Upload

Index.js：

var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function (req, res) {
    res.render('fileUpload', { title: 'Log File Viewer'});
});


var formidable = require('formidable'),
    fs = require('fs'),
    util = require('util'); //Used to print out everything about the log file


/* POST the file upload */
router.post('/upload', function (req, res) {

    var form = new formidable.IncomingForm();

    form.parse(req, function (err, fields, files) {

        fs.readFile(files.logName.path, function (err, data) {
            if (err) throw err;


            // TODO: Getting form value
            var numError = req.body.numErr;
            console.log(numError);


            var reDiaBtoa = /^(\[[^\]]*\]) (\w+?) (\[[^\]]*\]) (\([^)]*\)) (.*)$/gm;
            var outputToDisplay = " ";


            // Check to see if regex string works
            if (reDiaBtoa.test(data)) {

                var array = data.toString().split('\n');

                for (l in array) {

                    var logArray = (array[l]);

                }

                // Use numPrompt to retrieve user input for numErr
                var numPrompt = 10;

                // Reverse the array so the most recent errors will show
                var newArray = array.reverse();
                var match;
                //Count the number of errors in the log file
                var countErrors=0;
                var numCount = (countErrors-numPrompt);

                for (var j = -1; j <= newArray.length; j++) { // Since newArray[0] contains an empty string


                    while ((match = reDiaBtoa.exec(newArray[j])) != null) {

                        if (match.index === reDiaBtoa.lastIndex) {
                            reDiaBtoa.lastIndex++;
                        }

                        if (match[2] === "ERROR") {

                            countErrors++;

                            res.write('<p>' + "Time " + match[1] + '<br/>');
                            res.write("Thread Name: " + match[3] + '<br/>');
                            res.write("Source name & line number: " + match[4] + '<br/>');
                            res.write("Log Message: " + match[5] + '<br/>');
                            res.write('--------------------------------------' + '</p>');

                        }
                    }
                }
                console.log(countErrors);
            }
        })
    });
});

每当我运行程序时，它一直说numError是未定义的。我能够读取文件输入，但不能读取数字输入。有什么想法吗？

更新：这是完整的index.js文件。