No database selected แก้ยังไงค่ะ เพราะในโค้ด connect ดาต้าเบสใช้งานได้ปกติค่ะ ช่วยดูให้หน่อยค่ะ ขอบคุณค่ะ

<?php
   include'connect.php';
	session_start();
if (!empty($_POST['submit'])) {
	header("Location:login.html");
	exit();
}
$formusername=isset($_POST['form-username']) ? $_POST['form-username'] : '';
$test_query="SELECT * FROM login WHERE username = '".mysql_real_escape_string($formusername)."'";
$query_result=mysql_query($test_query) or die ($test_query .' '. mysql_error());
if(mysql_num_rows($query_result)==0) {
	echo "The username you entered is invalid.";
}else {
	while($row_query = mysql_fetch_array($query_result)){
		if($row_query['password']==$_POST['form-password']) {
			$_SESSION['password'] =$_POST['form-password'];
		header("Location:Home.php");
			exit();
	} else{
		echo "Password is not correct.";
	}
  }
}
?>

<?php
$host="localhost";
$user="root";
$pass="ad001";
$db="db_timetable";
$ObjCon=mysql_connect($host,$user,$pass,$db);

if($ObjCon)
{
	echo "Database Connected.";
}
else
{
	echo "Database Connected Failed : Error : ".mysql_error();
}

mysql_close($ObjCon);
?>