Denemedim. Gözümden kaçan birşey olmuş olabilir.

form.html
<form action="gonder.php?islem=yolla" method="post" name="contact" id="emailForm"> 
ISO 9001 <INPUT TYPE=CHECKBOX NAME="standart[]"  value="ISO-9001"> 
ISO 14001 <INPUT TYPE=CHECKBOX NAME="standart[]"  value="ISO-14001"> 
ISO 22000 <INPUT TYPE=CHECKBOX NAME="standart[]"  value="ISO-22000"> 
IOHSAS 18001 <INPUT TYPE=CHECKBOX NAME="standart[]"  value="IOHSAS-18001"> 
</from >
gonder.php
<?php 

$islem = $_GET['islem']; 
if ($islem == "yolla") { 
?>
ISO 9001 <INPUT <?php echo in_array('ISO-9001', (array)$_REQUEST['standart']) ? 'checked="checked"' : '' ?> TYPE=CHECKBOX NAME="standart[]"  value="ISO-9001"> 
ISO 14001 <INPUT <?php echo in_array('ISO-14001', (array)$_REQUEST['standart']) ? 'checked="checked"' : '' ?> TYPE=CHECKBOX NAME="standart[]"  value="ISO-14001"> 
ISO 22000 <INPUT <?php echo in_array('ISO-22000', (array)$_REQUEST['standart']) ? 'checked="checked"' : '' ?> TYPE=CHECKBOX NAME="standart[]"  value="ISO-22000"> 
IOHSAS 18001 <INPUT <?php echo in_array('IOHSAS-18001', (array)$_REQUEST['standart']) ? 'checked="checked"' : '' ?> TYPE=CHECKBOX NAME="standart[]"  value="IOHSAS-18001"> 
} 
?> 

<?php }>