satouriko · August 19, 2017 15:38
diff --git a/handle.php b/handle.php
 <?php

 session_start();

 $_SESSION['error'] = "Error!!!";
 header("Location: index.php");
diff --git a/index.php b/index.php
 <?php

 session_start();

 if(isset($_SESSION['error'])) {
        echo $_SESSION['error'];
        unset($_SESSION['error']);
 }

 ?>

 <form action="handle.php" method="post">
 <input type="submit" value="submit">
 </form>
	<?php

	session_start();

	if(isset($_SESSION['error'])) {
	echo $_SESSION['error'];
	unset($_SESSION['error']);
	}

	?>

	<form action="handle.php" method="post">
	<input type="submit" value="submit">
	</form>