The best way to deal with quotes and MySQL is to always use single quotes in your queries and use addslashes() at all times. Here's an example:
$name = addslashes ($HTTP_POST_VARS["name"]);
$description = addslashes ($HTTP_POST_VARS["description"]);
$rs = mysql_query ("SELECT * FROM profile WHERE name='$name'");
if ($rs && mysql_num_rows ($rs) > 0)
{
echo "Person with this name already exists, choose another.\n";
exit;
}
mysql_query ("INSERT INTO profile (name, description) VALUES ('$name', '$description');
echo "Added '", stripslashes ($name), "' succesfully.\n";
I haven't encountered a problem with this method yet.