<?php
$str = "Hello";
echo sha1($str);

if (sha1($str) == "f7ff9e8b7bb2e09b70935a5d785e0cc5d9d0abf0")
&nbsp;&nbsp;  {
&nbsp;&nbsp;  echo "<br>Hello world!";
&nbsp;&nbsp;  exit;
&nbsp;&nbsp;  }
?>