Notice: Use of undefined constant db - assumed

Jeg får følgende fejl når jeg trykker på [ADD]... Hvad er der galt?

Her er mine koder:
--- index.htm ---
<FORM ACTION="newsfunction.php" METHOD=POST>
Name<br>
<input type=text name="author" size=30><br>
Title<br>
<input type=text name="title" size=30><br>
E-Mail<br>
<input type=text name="email" size=30><br>
Story<br>
<textarea rows="2" name="story" cols="20"></textarea><br>
<input type="submit" name="submit" value="Add">
</FORM>
-------

--- newsfunction.php ---
<?php
include 'connect.php';
if ($submit) {
  $sql = "INSERT INTO news (title,author,email,story) VALUES ('$title','$author','$email','$story')";
  $result = mysql_query($sql);
    echo "DONE";
} else {
    echo "NOT DONE";
    }
mysql_close();
  ?>
-------

--- connect.php ---
<?
mysql_connect("localhost", "root", "");
mysql_select_db(db)
?>
-------

--- DATABASE ---
Feltnavn Datatype Nulværdi Standardværdi
id  int(5) Nej   
title  varchar(50) Nej   
author  varchar(50) Nej   
story  text Nej   
email  varchar(50) Nej   
time  timestamp(14) Ja  NULL