ขอความช่วยเหลือครับ $sql = "select * from ................. ไม่ยอมรับค่าตัวแปร

<?
include "connect.php";

$user = 'admin';
$password = '1234';

$sql = "select * from member where Username = '$user' and Password = '$password' ";
$result = mysql_db_query($dbname,$sql);
$num = mysql_num_rows($result);
mysql_close();

if($num<=0) {
echo "ERROR : Username and Password Incorrect!";
} else {
echo "---OK---";
}
?>