function getsubjectname($mysqli, $subjectid)
    {
        $query="select SubjectName from user_subject where SubjectId=?";
        $stmt=$mysqli->stmt_init();
        $stmt->prepare($query);
        $stmt->bind_param('i', $subjectid);
        $stmt->execute();
        $stmt->bind_result($SubjectName);
        $stmt->fetch();
        return $SubjectName;

    }

<div style='font-size:24px;'> <?php if(!isset($_GET['subjectid'])){$row=getpinnedsubject($mysqli, $userid); echo $row['SubjectName']; } else {  echo getsubjectname($mysqli, $_GET['subjectid']);}?></div>