//ciasteczka
//sesja
<form action="<?=$fn?>" method="GET">
File: <br>
<input type="text" name="filename">
</form><br>
<?php
$fn = $_GET["filename"];
$file_handle = fopen($fn, "r");
$text_data = fread($file_handle, filesize($fn));
fclose($file_handle);
?>

<form id="stupidform" action="editor1.php?filename=<?=$fn?>" method="POST" accept-charset="UTF-8">
<!--
<textarea name="valdata" cols="80" rows="40">
<?=$text_data?>
</textarea>
-->

<div id="aceEditor" style="height: 500px; width: 500px"><?=$text_data?></div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/ace/1.1.8/ace.js" type="text/javascript" charset="utf-8"></script>
<script>
var editor = ace.edit("aceEditor");
var code = editor.getSession().getValue();
document.getElementById("codeee").innerHTML = code;
</script>
<textarea name="codeee">
</textarea>
<br />
<input type="submit" name="codee" />
</form>