mysqli create database

<?php
$dbhost = 'localhost'; // host name
$dbuser = 'root'; //user name
$dbpass = ''; // password
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
  die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
$sql = 'CREATE Database question_bank';
$retval = mysqli_query($conn , $sql);
if(! $retval )
{
  die('Could not create database: ' . mysqli_error($conn));
}
echo "Database question_bank created successfully\n";
mysqli_close($conn);
?>