รบกวนพี่ๆช่วยดู code login ให้ผมหน่อยครับ ว่า มันผิดตรงไหนถึง login ไม่ได้อ่ะครับ

<?php
ob_start(); 
session_start();

	include '../inc/function.php';
	$dblink = connect_db();
	$username = $_POST[username];
	$password = $_POST[password];

	$strsqla = "SELECT *
				from tbl_admin
				where status !='0'
				and ad_User = '$username'
				and ad_Pass = md5('$password')";
				//echo "strsqla";

	$resultsqla = mysqli_query($dblink, $strsqla);
	$rowsa = mysqli_fetch_array($resultsqla);
	$numrowsa = mysqli_num_rows($resultsqla);

	$strsqlm = "SELECT *
				from tbl_user
				where mem_Status !='0'
				and mem_User = '$username'
				and mem_Pass = md5('$password')";
				//echo "$strsqlt";
				//exit();
	$resultsqlm = mysqli_query($dblink, $strsqlm);
	$rowsm = mysqli_fetch_array($resultsqlm);
	$numrowsm = mysqli_num_rows($resultsqlm);

	if ($numrowsa > 0) {
		$_SESSION["ad_Id"] = $rowsa["ad_Id"];
		echo "you admin";
		//echo "<meta http-equiv='refresh' content='2 ; url=adm_manage.php'>";
	}elseif ($numrowsm > 0) {
		$_SESSION["mem_Id] = $rowst[mem_Id"];
		echo "you user";
		//echo "<meta http-equiv='refresh' content='2 ; url=tea_manage.php'>";
	}

?>

 <form id="form1" name="form1" method="POST" action="chklogin.php" role="form">
                            <fieldset>
                                <div class="form-group">
                                    <input class="form-control" placeholder="ชื่อผู้ใช้" name="username" type="text">
                                </div>    
                                <div class="form-group">
                                    <input class="form-control" placeholder="รหัสผ่าน" name="password" type="password" >
                                </div>
                                <!-- Change this to a button or input when using this as a form -->
                                <button type="submit" class="btn btn-outline btn-primary">เข้าสู่ระบบ</button> <a href="index.php" type="button" class="btn btn-danger" >ยกเลิก</a>
                            </fieldset>
                        </form>