Vise værdi fra database i value (udvidelse)

Jeg har denne side som virker fortrinligt. MEn hvis jeg vil udvide den, så den trækker en værdi ud fra feltet i en database, sker der en masse ting, den kommer ikke med fejl. Men synes ikke jeg kan få det til at virke optimalt.

Så opgaven går på at den skal trække værdien ud fra felterne i databasen, og vise dem i value feltet i formen. Der skal kun trækkes ud hvor imei = $_GET['imei'] og usermark = $usermark. Det er de eneste krav.

De felter der skal trækkes ud hedder det samme som name feltet i formen. Her er scriptet:

<?
session_start();
header("Cache-control: private");
require("inc/conn_inc.php");
session_checker();
?>
<html>
<head>
<title>edit.php</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>

<br><br>
<?

$errors = array();
$fejl = 5;
#carbrand check
if(isset($_POST['carbrand'])) {
  if(trim($_POST['carbrand']) == '') $errors['carbrand'] = "<font color='#FF3300'>Field Carbrand is required</font>.";
  else $fejl--;
}
else $errors['carbrand'] = "*";

#carmodel check
if(isset($_POST['carmodel'])) {
  if(trim($_POST['carmodel']) == '') $errors['carmodel'] = "<font color='#FF3300'>Field Carmodel is required</font>.";
  else $fejl--;
}
else $errors['carmodel'] = "*";

#devicenumber check
if(isset($_POST['devicenumber'])) {
  if(trim($_POST['devicenumber']) == '') $errors['devicenumber'] = "<font color='#FF3300'>Field Devicenumber is required</font>.";
  else $fejl--;
}
else $errors['devicenumber'] = "*";

#unitid check
if(isset($_POST['unitid'])) {
  if(trim($_POST['unitid']) == '') $errors['unitid'] = "<font color='#FF3300'>Field Unitid is required</font>.";
  else $fejl--;
}
else $errors['unitid'] = "*";

#mainnumber check
if(isset($_POST['mainnumber'])) {
  if(trim($_POST['mainnumber']) == '') $errors['mainnumber'] = "<font color='#FF3300'>Field Mainnumber is required</font>.";
  else $fejl--;
}
else $errors['mainnumber'] = "*";



if(!$fejl){
  $carbrand = $_POST['carbrand'];
  $carmodel = $_POST['carmodel'];
  $devicenumber = $_POST['devicenumber'];
  $unitid = $_POST['unitid'];
  $mainnumber = $_POST['mainnumber'];
  $vip1 = $_POST['vip1'];
  $vip2 = $_POST['vip2'];
  $vip3 = $_POST['vip3'];
  $vip4 = $_POST['vip4'];
  $vip5 = $_POST['vip5'];
  $vip6 = $_POST['vip6'];

#strip out specialchars (security)
$carbrand = htmlspecialchars($carbrand,ENT_QUOTES);
$carmodel = htmlspecialchars($carmodel,ENT_QUOTES);
$devicenumber = htmlspecialchars($devicenumber,ENT_QUOTES);
$mainnumber = htmlspecialchars($mainnumber,ENT_QUOTES);
$vip1 = htmlspecialchars($vip1,ENT_QUOTES);
$vip2 = htmlspecialchars($vip2,ENT_QUOTES);
$vip3 = htmlspecialchars($vip3,ENT_QUOTES);
$vip4 = htmlspecialchars($vip4,ENT_QUOTES);
$vip5 = htmlspecialchars($vip5,ENT_QUOTES);
$vip6 = htmlspecialchars($vip6,ENT_QUOTES);
$sql = ("UPDATE x8unit SET carbrand = '$carbrand',carmodel = '$carmodel',devicenumber = '$devicenumber',
    unitid = '$unitid',mainnumber = '$mainnumber',vip1 = '$vip1',vip2 = '$vip2',vip3 = '$vip3',vip4 = '$vip4',vip5 = '$vip5',vip6 = '$vip6',
    WHERE imei='$imei'") or die(mysql_error());
mysql_query($sql) or die(mysql_error());

if(!$sql){
    print "<font color='#FF3300'>There has been an error editing your device. Please contact the webmaster.</font><br /><br />";
} else {
    print "<font color='#008000'>Your device was successfully edited.
    <script type=\"text/javascript\">setTimeout(\"location.href='login_success.php?action=EditDevice';\",3000);</script>
    <br /><br /></font>";
}
}


<form action="edit.php" method="post">
Carbrand:<br>
<input type="text" name="carbrand" class="inputfield">
<? if(isset($errors['carbrand'])) print $errors['carbrand']; ?><br>
Carmodel:<br>
<input type="text" name="carmodel" class="inputfield">
<? if(isset($errors['carmodel'])) print $errors['carmodel']; ?><br>
Devicenumber:<br>
<input type="text" name="devicenumber" class="inputfield">
<? if(isset($errors['devicenumber'])) print $errors['devicenumber']; ?><br>
Unitid:<br>
<input type="text" name="unitid" class="inputfield">
<? if(isset($errors['unitid'])) print $errors['unitid']; ?><br>
mainnumber:<br>
<input type="text" name="mainnumber" class="inputfield">
<? if(isset($errors['mainnumber'])) print $errors['mainnumber']; ?><br>
vip1:<br>
<input type="text" name="vip1" class="inputfield"><br>
vip2:<br>
<input type="text" name="vip2" class="inputfield"><br>
vip3:<br>
<input type="text" name="vip3" class="inputfield"><br>
vip4:<br>
<input type="text" name="vip4" class="inputfield"><br>
vip5:<br>
<input type="text" name="vip5" class="inputfield"><br>
vip6:<br>
<input type="text" name="vip6" class="inputfield"><br><br>
<input type="submit" name="EditDevice" value="Edit device" class="inputbutton"><br><br>
</form>
* Marked fields are required!
</body>
</html>
<?

mysql_close($conn);
?>