Add records to mysql

[birchtrees]

Hello,
Could someone please explain how I can Update a data base with this code

$link = mysql_connect("localhost", "pelicandecal", "pelsto");
mysql_select_db("pelicandecal", $link);
$result = mysql_query("UPDATE orders SET comp = '$compa', item1 = '$itema', item2 = '$itemb', item2 = '$itemc'
WHERE code = 1", $link);

but I can't Insert a new record with this code

$link = mysql_connect("localhost", "pelicandecal", "pelsto");
mysql_select_db("pelicandecal", $link);
$result = mysql_query ("INSERT INTO orders (code, comp, item1, item2, item3)
VALUES (Null, '$compa', '$itema','$itemb','$itemc' )",$link);

Thank-you very much

[edwardsbc]

Are you certain you have INSERT permission for the database? Is 'Code' allowed to be NULL? Why not just leave it out of the insert statement? What exactly is the error you are getting?