Formuläret:
...
<form action="dittPHPDoukument.php" method="POST">
<textarea id="minText" name="minText">
<?php
$fileList = file( "minTextFil.txt" );
while( $curLine = array_shift( $fileList ) )
echo $curLine . "\n";
?>
</textarea>
...
PHP:
<?php
$filePointer = fopen( "minTextFil.txt", 'w' );
fwrite( $filePointer, $_POST[ 'minText' ] );
fclose( $filePointer );
?>