aggiornare file txt

<input name="textfield" type="text" value='<?php echo $contenuto ?>'/>

<input name="textfield" type="text" value='<?php echo $contenuto ?>' readonly />

<input name="textfield" type="text" value='<?php echo $contenuto ?>'readonly style="border:0 ; background-color:#999999;" />

<style type="text/css">
<!--
body {
	background-color: #CCCCCC;
}
.casella{
	border:0;/*senza bordo*/
	background-color:transparent;/*sfondo trasparente*/
	text-align: right;/*testo allineato a dx*/
	color:#FF0000;/*colore del testo*/
}
-->
</style>
<?php
$b="pinco";
$contenuto="pallo";
?>
<input size="30" name="textfield" type="text" value="<?php echo $b . " " . $contenuto?>" readonly class="casella"/>