SQL- MEERDERE AND (Opgelost)

<?php
error_reporting(E_ALL);
$con = mysql_connect("localhost","***","***");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("raamdecora_db1", $con);

$result = mysql_query("SELECT * FROM klanten WHERE groep_gordijnstoffen='1' AND postcode=('8900','8700')");
//$result = mysql_query("SELECT * FROM klanten WHERE groep_gordijnstoffen='1' AND postcode='8900'");

echo "<table border='1'>
<tr>
<th>ID</th>
<th>Firma</th>
<th>Straat</th>
<th>Postcode</th>
<th>Stad</th>
<th>Tel</th>
<th>Email</th>
<th>Website</th>
<th>Groep gordijnstoffen</th>
</tr>";

while($row = mysql_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['firmaID'] . "</td>";
  echo "<td>" . $row['firma'] . "</td>";
  echo "<td>" . $row['straat'] . "</td>";
  echo "<td>" . $row['postcode'] . "</td>";
  echo "<td>" . $row['stad'] . "</td>";
  echo "<td>" . $row['tel'] . "</td>";  
  echo "<td>" . $row['email'] . "</td>";
  echo "<td>" . $row['website'] . "</td>";    
  echo "<td>" . $row['groep_gordijnstoffen'] . "</td>";
  echo "</tr>";
  }
echo "</table>";
?> 

<?php
error_reporting(E_ALL);
$con = mysql_connect("localhost","***","***");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
 
mysql_select_db("raamdecora_db1", $con);
 
$result = mysql_query("SELECT * FROM klanten WHERE groep_gordijnstoffen='1' AND postcode=('8900','8700')");
//$result = mysql_query("SELECT * FROM klanten WHERE groep_gordijnstoffen='1' AND postcode='8900'");
 
echo "<table border='1'>
<tr>
<th>ID</th>
<th>Firma</th>
<th>Straat</th>
<th>Postcode</th>
<th>Stad</th>
<th>Tel</th>
<th>Email</th>
<th>Website</th>
<th>Groep gordijnstoffen</th>
</tr>";
 
while($row = mysql_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['firmaID'] . "</td>";
  echo "<td>" . $row['firma'] . "</td>";
  echo "<td>" . $row['straat'] . "</td>";
  echo "<td>" . $row['postcode'] . "</td>";
  echo "<td>" . $row['stad'] . "</td>";
  echo "<td>" . $row['tel'] . "</td>";  
  echo "<td>" . $row['email'] . "</td>";
  echo "<td>" . $row['website'] . "</td>";    
  echo "<td>" . $row['groep_gordijnstoffen'] . "</td>";
  echo "</tr>";
  }
echo "</table>";
?>