ระบบไม่ทำการตรวจชื่อผู้ใช้ซ้ำก่อนทำการบันทึกลงฐานข้อมูล

<?
$name_artist=$_POST['name_artist'];
$detail_artist=$_POST['detail_artist'];

$photo=$_FILES['photo']['tmp_name'];
$photo_name=$_FILES['photo']['name'];
$photo_size=$_FILES['photo']['size'];
$photo_type=$_FILES['photo']['type'];


if ($name_artist=="" or $detail_artist=="") {
	echo "<H2>เพิ่มไม่สำเร็จ</H2>";
	echo "[ <A HREF=artist_add.php>กลับหน้าหลักศิลปิน</A> ] ";
	exit();
}

include "connect.php";
$strSQL = "SELECT * FROM artist WHERE name_artist = '".trim($_POST['name_artist'])."' ";
	$objQuery = mysql_query($strSQL);
	$objResult = mysql_fetch_array($objQuery);
	if($objResult)
	{
			echo "ชื่อซ้ำโปรดใช้ชื่ออื่น";
	}
else

include "connect.php";
$sql="INSERT INTO artist 
VALUES(null,'$name_artist','$detail_artist','')";
mysql_db_query("$dbname",$sql);

$ext = strtolower(end(explode('.', $photo_name)));
if ($ext == "jpg" or $ext == "jpeg" or $ext=="gif" or $ext=="png") {

	$sql="select max(id_artist) from artist";
	$result=mysql_db_query($dbname,$sql);
	$r=mysql_fetch_array($result);
	$id_max=$r[0];

	$filename=$id_max.".".$ext;
	copy($photo,"photoartist/$filename");

	$sql="update artist set picture_artist='$filename' where id_artist='$id_max' ";
	mysql_db_query($dbname,$sql);

}
echo "<H3>เพิ่มข้อมูลสำเร็จ</H3>";
echo "[ <A HREF=artist.php>กลับหน้าหลัก</A> ] ";
mysql_close();
?>