Can't use demo: Unknown database 'demo'

I have this error when i try to submit to my demo database: Can't use demo: Unknown database 'demo' How do i get the server going?

Basic form:

<form action="demo.php" method="post" />
<p>Input 1: <input type="text" name="input1" /></p>
<p>Input 2: <input type="text" name="input2" /></p>
<input type="submit" value="Submit" />
</form>

Server communication setup:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Untitled Document</title>
</head>

<body>


<?php

define('DB_NAME', 'demo');
define('DB_USER', 'root');
define('DB_PASSWORD', 'root');
define('DB_HOST', 'localhost');

$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);

if (!$link) {
    die('Could not connect: ' . mysql_error());
}

$db_selected = mysql_select_db(DB_NAME, $link);

if (!$db_selected) {
    die('Can\'t use ' . DB_NAME . ': ' . mysql_error());
}

$value = $_POST['input1'];
$value2 = $_POST['input2'];

$sql = "INSERT INTO demo (input1, input2) VALUES ('$value', '$value2')";

if (!mysql_query($sql)) {
    die('Error: ' . mysql_error());
}

mysql_close();
?>

</body>
</html>

All my code should work and is from this tutorial: Tutorial video link
Here is download link to the original php files i have used: Original from tutorial: Basic php form Orignial from tutorial: Communication with server php-file

Solution

Your database name is forms1 not demo. demo is your table name

Try this code

define('DB_NAME', 'forms1');//Your database name is forms1 not demo
define('DB_USER', 'root');
define('DB_PASSWORD', 'root');
define('DB_HOST', 'localhost');

$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);

if (!$link) {
    die('Could not connect: ' . mysql_error());
}

$db_selected = mysql_select_db(DB_NAME, $link);

if (!$db_selected) {
    die('Can\'t use ' . DB_NAME . ': ' . mysql_error());
}

Change this code because in your table column input2 not available

$sql = "INSERT INTO demo (input1) VALUES ('$value')";