Question: One of the reasons that I moved from emacs to vim was to avoid awkward keybindings such as Ctrl+N and Ctrl+P for up and down. I would prefer more ergonomic keys like hjkl. However, I didn't find a way to navigate in Omnicomplete box without using arrow keys or Ctrl+N/P.

Does vim provide other keys for up and down?

![enter image description here](https://i.stack.imgur.com/nwyyr.png)

Answer: 
If you successfully installed EXPRESS but then also you get
***ReferenceError: express is not defined.***

Then,

just put name of variable in first line and function name in second line same like this:-

```
var express = require('express');  
var app = express();

```

Not Like This:-

```
var exp = require('express');  
var app = express();

```
check the file permissions also please. Also may be your user login do not have the permission to make changes in the system. You may have to use sudo before the command to do so if you are on ubuntu or not a root user.