i need help with php scripting..

what im doing is pretty simple but i have about.. well.. no experence with php =\
okie, im making a HTTP proxy site with the free script PHProxy. i want to add a feature where it requires a preset username and password.
example: i want just 1 username and password to be able to get into the site
so a few of my freinds can get into the site threw school and it won't lag down my server
the download site is
http://whitefyre.com/poxy/
actuly if you can intergrade it into the script using the username "ipwnrake" and the password "cheese"
that would be great to, remember, im terrable when it comes to php =\
thanks in advance
-chuck white.

EDIT: i've jacked a sorce from another site, its almost want i want but it dosn't have a preset username and such.

PHP:

<input  ype="text"  name="username" />
  </p>
  <p> Password</p>

  <p><input type=text  name=password />&nbsp; </p>
  <input type=submit value="Login" />
  </form>
  
</div></center></td>
   <td><img src="images/spacer.gif" width="1" height="280" border="0" alt="" /></td>
  </tr>
  <tr>
   <td>   <br /><br /><div id="Login" style="border:solid; border-width:thin;">

   <div style="margin-left:10px; margin-right:10px; margin-top:10px; margin-bottom:10px;">
  <p align="left" ><strong>Create Account </strong></p><p  style="margin-bottom:8px;" >
  <form action="secure.php" method="post">
<input type=hidden name=act value=login>
<p>School ID </p>
<p  style="margin-bottom:5px;" >
  <p>

 

Code:

<?php
if(isset($_GET['check'])) {
$un = $_POST['un'];
$pw = $_POST['pw'];
if($un == "ipwnrake" && $pw == "cheese") {
//put your proxy or whatever here (remove the //)
}
else {
echo "wrong pw/un combo.";
echo "";
}
else {
?>
<form action="?check" method="post">
<input type="text" name="un" value="username">
<input type="password" name="pw" value="password">
<input type="submit" name="submit" value="login">
</form>
<?php
}
?>

Just made that up on the spot; have no place to test it. There shouldn't be any errors though.