i need help passing $user data to echo data area of my new file being created.

#!/bin/sh
 
echo -n "enter username: "
read user
echo -n "enter Wordpress' latest version number: "
read version
cd /home/$user/public_html
#download latest files for installation from wordpress.org
wget http://wordpress.org/latest.tar.gz
tar xvzf latest.tar.gz
tar xvzf wordpress-$version.tar.gz
chown -R $user.$user /home/$user/public_html/wordpress
 
touch /home/$user/public_html/wordpress/wp-config.php
echo "<?php
// ** MySQL settings ** //
 
// THE LINES THAT NEED THE $user DATA PASSED from above on line3
define('DB_NAME', '\$user_wpdb');    // The name of the database
define('DB_USER', '\$user_wp');     // Your MySQL username
define('DB_PASSWORD', '*******'); // ...and password
define('DB_HOST', 'localhost');    // 99% chance you won't need to change this value
define('DB_CHARSET', 'utf8');
define('DB_COLLATE', '');
 
// Change SECRET_KEY to a unique phrase.  You won't have to remember it later,
// so make it long and complicated.  You can visit http://api.wordpress.org/secret-key/1.0/
// to get a secret key generated for you, or just make something up.
define('SECRET_KEY', 'put your unique phrase here'); // Change this to a unique phrase.
 
// You can have multiple installations in one database if you give each a unique prefix
\$table_prefix  = 'wp_';   // Only numbers, letters, and underscores please!
 
// Change this to localize WordPress.  A corresponding MO file for the
// chosen language must be installed to wp-content/languages.
// For example, install de.mo to wp-content/languages and set WPLANG to 'de'
// to enable German language support.
define ('WPLANG', 'en');
 
/* That's all, stop editing! Happy blogging. */
 
define('ABSPATH', dirname(__FILE__).'/');
require_once(ABSPATH.'wp-settings.php');
?>" > /home/$user/public_html/wordpress/wp-config.php
 
 
#Cleaning up
rm -rf latest.tar.gz
rm -rf wordpress-$version.tar.gz
 
echo "CREATE database "$user"_wpdb" | mysql
echo "GRANT ALL PRIVILEGES ON ${user}_wp.* TO '"$user"_wp'@'localhost' IDENTIFIED BY 'Access1x2' WITH GRANT OPTION " | mysql
echo "GRANT ALL on ${user}_wp.* TO '"$user"_wp'@'localhost'" | mysql
echo "flush privileges" | mysql
 
echo "to continue installation, go to: http://216.83.111.31/~$user/wordpress"