Opdater MySQL?

Hvorfor vil min rediger side ikke opdater felter i mysql?

Jeg har ikke så meget styr på mysql, men er dog ved at lære det :D

<?
$skriv = $_REQUEST["skriv"];
$besked = $_REQUEST["besked"];

if (is_array($_GET))
{
$nr = $_GET['nr'];
}

$username = "Jolly";
$password = "050684";

$user = $HTTP_COOKIE_VARS["user"];
$pass = $HTTP_COOKIE_VARS["pass"];

if ($skriv)
{

if (($user == $username) && ($pass == $password))
{
$db = mysql_connect("jolly","root","050684");
mysql_select_db("gbog",$db);
$besked = str_replace("\n","<br>",$besked);
mysql_query("UPDATE bog WHERE nr = $nr(besked) VALUES ('$besked')");
mysql_close;
header('Location: tagwall.php');
}
else
{
include("style.php");
?>
<body bgcolor="#707070">
<center>
<table width='300' border='0' celpadding='0' cellspacing='0' bgcolor='#000000'>
  <tr>
    <td BGCOLOR="#000000">
      <table width='100%' height='100%' border='0' celpadding='0' cellspacing='0'>
        <TR>
          <TD bgcolor='#eeeeee'>
          <center>Hvad har du gang i?<br>
          <a href='tagwall.php'>Tilbage igen</A></CENTER>
          </td>
        </tr>
      </TABLE>
    </td>
  </tr>
</table> 
</center>
<?
}
}
else
{

$db = mysql_connect("jolly","root","050684");
mysql_select_db("gbog",$db);
?>

<HTML>
<HEAD><TITLE>TAGWALL</TITLE>
</HEAD>
<?php
include("style.php");
?>
<body bgcolor="#707070">
<center>
<table width='500' border='0' celpadding='0' cellspacing='0' bgcolor='#000000'>
  <tr>
    <td>
      <table width='100%' height='100%' border='0' celpadding='0' cellspacing='0'>
        <TR>
          <TD bgcolor='#CFCFCF' VALIGN=TOP>
            <center>Rediger</Center>
          </TD>
        </TR>
      </TABLE>
    </td>
  </tr>
</table>
<br>
<?

$foresp=mysql_query("SELECT nr,navn,email,besked FROM bog Where nr = $nr");
$data = mysql_fetch_row($foresp);

$data[3] = str_replace("<br>","\n",$data[3]);

echo "<table width='300' border='0' celpadding='0' cellspacing='0' bgcolor='#000000'>\n";
echo "  <tr>\n";
echo "    <td BGCOLOR='#000000'>\n";
echo "      <table width='100%' height='100%' border='0' celpadding='0' cellspacing='0'>\n";
echo "        <TR>\n";
echo "          <TD bgcolor='#eeeeee' VALIGN=TOP>\n";
echo "            <FORM METHOD=POST ACTION='rediger.php?nr=$data[0]'>\n";
echo "            <INPUT TYPE=hidden NAME=skriv Value=1>\n";
echo "            <TABLE BORDER='0' CELLSPACING='1' ALIGN='center'>\n";
echo "              <TR HEIGHT='30' VALIGN='bottom'>\n";
echo "                <TD>Navn:</TD>\n";
echo "                <TD>$data[1]</TD>\n";
echo "              </TR>\n";
echo "              <TR>\n";
echo "                <TD>E-mail:</TD>\n";
echo "                <TD>$data[2]</TD>\n";
echo "              </TR>\n";
echo "            </TABLE>\n";
echo "          </TD>\n";
echo "        </TR>\n";
echo "        <TR BGCOLOR='#FFFFFF'>\n";
echo "          <TD bgcolor='#eeeeee' ALIGN='center'>\n";
echo "            <TEXTAREA NAME=besked COLS=30 ROWS=6>$data[3]</TEXTAREA>\n";
echo "            <BR>\n";
echo "          </TD>\n";
echo "        </TR>\n";
echo "        <TR BGCOLOR='#FFFFFF'>\n";
echo "            <TD bgcolor='#eeeeee' ALIGN='center' HEIGHT='50' VALIGN='bottom'>\n";
echo "            <INPUT TYPE=submit value=Send>\n";
echo "            </FORM>\n";
echo "          </TD>\n";
echo "        </TR>\n";   
echo "        </TR>\n";
echo "      </TABLE>\n";
echo "    </td>\n";
echo "  </tr>\n";
echo "</table>\n";
echo "<br>\n";
echo "<table width='500' border='0' celpadding='0' cellspacing='0' bgcolor='#000000'>\n";
echo "  <tr>\n";
echo "    <td>\n";
echo "      <table width='100%' height='100%' border='0' celpadding='0' cellspacing='0'>\n";
echo "        <TR>\n";
echo "          <TD bgcolor='#CFCFCF' VALIGN=TOP>\n";
echo "            <center><a href='tagwall.php'>Tilbage</A>\n";
echo "          </TD>\n";
echo "        </TR>\n";
echo "      </TABLE>\n";
echo "    </td>\n";
echo "  </tr>\n";
echo "</table>\n";
echo "</CENTER>\n";
echo "</BODY>\n";
echo "</HTML>\n";
}
?>