Trying to add a anchor link to the contents body using the content title

I have created a simple comment system in Express using MongoDB. The user simply uses the form on the home screen to enter a title & a comment and it then appears in a list on the bottom of the page.

However, Before it was simply showing the comments title and body on the page, what I wanted to try and do was to link the title so that when you clicked on it, it showed the comments content.

My model:

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var CommentSchema = new Schema({
    title: String,
    content: String,
    created: Date
});

module.exports = mongoose.model('Comment', CommentSchema);

My view:

extends layout

block content
  h1= title
  div.addCommentForm
        form( method="post", action="/create")
            div
                div
                    span.label Title :
                    input(type="text", class="nameTxt", name="title")
                div
                    span.label Comment :
                    textarea(name="comment")
                div#addCommentSubmit
                    input(type="submit", value="Save")
  br
  br
  #comments
    - each comment in comments
      div.comment
        a(href=comment.title) #{comment.title}
        div.name= comment.title
        div.content= comment.content 
        hr

My app.js:

require('./models/comments'); // require the model before the 'index.js' file is called

var express = require('express');
var path = require('path');
var favicon = require('static-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var create = require('./routes/create');
var show = require('./routes/show');

var app = express();

// Database stuff
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/comments-app');

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon());
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/create', create);
**app.use('/:comment.title', show)**; // add to render the comments content

/// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

/// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});


module.exports = app;

My show route:

var express = require('express');
var router = express.Router();
var mongoose = require('mongoose');
var Comment = mongoose.model('Comment', Comment);

router.get('/:comment.title', function(req, res) {
    res.send(comment.content)
});

module.exports = router;

When I click on the comments title in my app, I am presented with this rather long error.

Not Found

404

Error: Not Found
    at Layer.app.use.res.render.message [as handle] (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/app.js:37:15)
    at trim_prefix (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:240:15)
    at /Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:208:9
    at Function.proto.process_params (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:269:12)
    at next (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:199:19)
    at next (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:176:38)
    at next (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:176:38)
    at /Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:137:5
    at /Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:250:10
    at next (/Users/Keva161/Documents/Projects/Webapps/Node/Express4-Comments-Mongoose/node_modules/express/lib/router/index.js:160:14)

Any ideas on why I am getting this error and how I can possibly fix it so I am getting the intended behaviour?