<form method="post" action="
<?php
echo
$PHP_SELF
;
?>
"><br/>
<input type="text" size="20" maxlength="20" name="ip">
<?php
$ip
=
$_POST
[
"ip"
]
;
$host
=
gethostbyname
(
$ip
)
;
echo
"<input type='text' value='"
.
$host
.
"' />
\n
"
;
?>