View difference between Paste ID: ddaE4Ufh and CqsSW4jh

 <?php
 session_start();
 include 'database.php';
 
-if(!empty($_POST)){
+//if(!empty($_POST)){
-
+if(isset($_POST['username'])){
     $username = $_POST['username'];
     $password = $_POST['password'];
 
     $sql = "select * from user where username='".$username."' and password='".$password."'";
     #echo $sql."<br />";
     $query = mysql_query($sql) or die (mysql_error());
 
     // pengecekan query valid atau tidak
     if($query){
         $row = mysql_num_rows($query);
 
         // jika $row > 0 atau username dan password ditemukan
         if($row > 0){
             $_SESSION['isLoggedIn']=1;
             $_SESSION['username']=$username;
             header('Location: memberarea.php');
         }else{
             echo "username atau password salah";
         }
     }
 }
 ?>
 
 
 <html>
 
 
 <head>
 
 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">
 
 <!-- Optional theme -->
 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap-theme.min.css" integrity="sha384-fLW2N01lMqjakBkx3l/M9EahuwpSfeNvV63J5ezn3uZzapT0u7EYsXMjQV+0En5r" crossorigin="anonymous">
 
 <!-- Latest compiled and minified JavaScript -->
 <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js" integrity="sha384-0mSbJDEHialfmuBBQP6A4Qrprq5OVfW37PRR3j5ELqxss1yVqOtnepnHVP9aJ7xS" crossorigin="anonymous"></script>
 </head>
 
 <body>
 
 
 <nav class="navbar navbar-default">
   <div class="container-fluid">
     <!-- Brand and toggle get grouped for better mobile display -->
     <div class="navbar-header">
       <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
         <span class="sr-only">Toggle navigation</span>
         <span class="icon-bar"></span>
         <span class="icon-bar"></span>
         <span class="icon-bar"></span>
       </button>
       <a class="navbar-brand" href="#">Home</a>
     </div>
 
     <!-- Collect the nav links, forms, and other content for toggling -->
     <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
       <ul class="nav navbar-nav">
 
         <li><a href="#">About</a></li>
         <li class="dropdown">
           <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Fiture <span class="caret"></span></a>
           <ul class="dropdown-menu">
             <li><a href="#">Action</a></li>
             <li><a href="#">Another action</a></li>
             <li><a href="#">Something else here</a></li>
             <li role="separator" class="divider"></li>
             <li><a href="#">Separated link</a></li>
             <li role="separator" class="divider"></li>
             <li><a href="#">One more separated link</a></li>
           </ul>
         </li>
       </ul>
       <form class="navbar-form navbar-left" role="search">
         <div class="form-group">
           <input type="text" class="form-control" placeholder="Search">
         </div>
         <button type="submit" class="btn btn-default">Submit</button>
       </form>
       <ul class="nav navbar-nav navbar-right">
         <li><a href="#">Register</a></li>
         <li class="dropdown">
           <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Account <span class="caret"></span></a>
           <ul class="dropdown-menu">
             <li><a href="#">Action</a></li>
             <li><a href="#">Another action</a></li>
             <li><a href="#">Something else here</a></li>
             <li role="separator" class="divider"></li>
             <li><a href="#">Separated link</a></li>
           </ul>
         </li>
       </ul>
     </div><!-- /.navbar-collapse -->
   </div><!-- /.container-fluid -->
 </nav>
 
 
 
 <!--BAGIAN NAV ATAS-->
 
 
 <div class="container">
 <div class="row">
 
   <div class="col-md-8"> <!--KIRI-->
   <div class="panel panel-default">
   <div class="panel-heading">Post Wlahar</div>
   <div class="panel-body">
 <?php
-  $post = $_GET["post"];
+  //$post = isset($_GET["post"];
-  if (!$post) {
+  //if (!$post) {
  if(isset($_GET['post'])){
   $ambil_data = mysql_query("select * from berita order by id_berita desc limit 0,5");
   while($hasil_data = mysql_fetch_array($ambil_data)){
   ?>
    <div class="row-fluid">
      <div class="span4">
       <img data-src="holder.js/300x200" alt="300x200" src="<?=$hasil_data['gambar'];?>" style="width: 300px; height: 200px;">
     </div>
      <div class="span8">
        <h2><?=$hasil_data['judul'];?></h2>
     <p style="text-align:justify;"><?=substr($hasil_data['isi'],0,500);?></p>
       <p>
         <a href="index.php?post=<?=$hasil_data['id_berita'];?>" class="btn btn-primary">Baca Selengkapnya</a>
         <a href="#" class="btn btn-inverse">Diposkan pada <?=$hasil_data['tanggal'];?></a>
       </p>
     </div>
     </div>
     <hr>
  <?php
   }  }
   else
   {
 
   $ambil_data = mysql_query("select * from berita where id_berita='$post'");
  $hasil_data = mysql_fetch_array($ambil_data);
  ?>
   <div class="paragraphs">
    <div class="row">
    <div class="span12 well">
      <img class="img-polaroid" src="<?=$hasil_data['gambar'];?>" style="width:250px; height: 200px; float:left; margin-right:10px;"/>
      <div class="content-heading"><h3><?=$hasil_data['judul'];?></h3></div>
      <p><a href="#" class="btn btn-inverse">Diposkan pada <?=$hasil_data['tanggal'];?></a> </p>
      <p style="text-align:justify;"><?=$hasil_data['isi'];?></p>
      <div style="clear:both;"></div>
     </div>
    </div>
   </div>
 
 
     <?php
   $ambil_recent = mysql_query("select id_berita,judul,tanggal from berita order by rand() limit 20");
  ?>
   <div class="well sidebar-nav">
     <ul class="nav nav-list">
 
 
      <li class="nav-header">Baca Juga</li>
       <ul type="square">
        <?php
     while($hasil_recent= mysql_fetch_array($ambil_recent)){
        echo "<li><a href='index.php?link=lihatDetailBerita.php&id=$hasil_recent[id_berita]'>".$hasil_recent['judul']."</a></li>";
     }
     ?>
       </ul>
     </ul>
   </div>
 
 <?php
   }
  ?>
   </div>
 </div>
 
 
 
 
   </div>
   <div class="col-md-4"> <!--KANAN-->
 
   <div class="panel panel-primary">
   <div class="panel-heading">Member Area</div>
   <div class="panel-body">
 
 
 
   <!--LOGIN-->
 
   <form action="" method="post">
   <div class="form-group">
     <label for="exampleInputEmail1">Username</label>
     <input type="text" name="username" class="form-control" id="exampleInputEmail1" placeholder="Email">
   </div>
   <div class="form-group">
     <label for="exampleInputPassword1">Password</label>
     <input type="password" name="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
   </div>
 
 
   <button type="submit" class="btn btn-default">LOGIN</button>
 </form>
 
   <!--LOGIN-->
   </div>
 </div>
 
 
 
 
   </div>
 </div>
 </div>
 </div>
 
 <!--KONTEN-->
 
 
 
 <hr>
 	<footer class="footer">
 	<div class="container">
 
 	<center> <p class="text-muted"> Wlahar - 2016 </p> </center>
 	</div>
 	</footer>
 
 </body>