PHP edit file on server?

[Gaijin]

I can seem to find any reference to the "undefined index: page"...

Code:

<form action="<?php echo $_SERVER["PHP_SELF"] ?>" method="post">
    <textarea rows="10" cols="100" name="content"><?php readfile($fn); ?></textarea><br />
    <input type="submit" value="Save" VALUE="Refresh">  
</form>

And yet your script tries to locate it...

PHP Code:

$firstfile =  $_POST['page']; 


Cleared and should work, still not secure though...
Study the script and look at the changes before you just go on copy-pasting...

Code:

<?php

$firstfile =  (isset($_POST['page'])) ? $_POST['page'] : ((isset($_GET['page'])) ? $_GET['page'] : '');
echo $firstfile;   // the file is shown, and is there
$fn = $firstfile; // totally wasting resources and space: lulz


if (isset($_POST['content']))
{    
    $content = stripslashes($_POST['content']);
    $fp = fopen($fn,"w") or die ("Error opening file in write mode!"); // fopen($firstfile) // remove $fn
    fputs($fp,$content);
    
    fclose($fp) or die ("Error closing file!");
}
?>
<form action="<?php echo $_SERVER["PHP_SELF"].'?page={$firstfile}' ?>" method="post">
    <input type="text" name="page" value="{$firstfile}" /><br />
    <textarea rows="10" cols="100" name="content"><?php readfile($fn); ?></textarea><br />
    <input type="submit" value="Save" VALUE="Refresh">  
</form>