Here's a quickie for you (completely untested):
<?php
$emailTo="
[email protected]";
$reasons=array("I have a question","I've spotted a mistake","I would like a job");
if($_POST['submit']!="true"){
$reasonOptions="";
foreach($reasons as $key=>$value){$reasonOptions.="<option value='".($key+1)."'>".htmlentities($value)."</option>";}
echo "<head>\r\n"
."<title>Contact Us</title>\r\n"
."<style>body,td,input,textarea{font-family:arial,sans-serif;color:#777;}.b{font-weight:bold;}.r{text-align:right;}</style>\r\n"
."</head>\r\n"
."<body>\r\n"
."<form method='post'>\r\n"
."<input type='hidden' name='submit' value='true' />\r\n"
."<table>\r\n"
."<tr><td class='b r'>Habbo Name</td><td><input type='text' name='habboname' /></td></tr>\r\n"
."<tr><td class='b r'>Email</td><td><input type='text' name='emailaddress' /></td></tr>\r\n"
."<tr><td class='b r'>Reason</td><td><select name='reason'>{$reasonOptions}</select></td></tr>\r\n"
."<tr><td class='b r'>Message</td><td><textarea name='message'></textarea></td></tr>\r\n"
."<tr><td></td><td><input type='submit' value='Send Message »' /></td></tr>\r\n"
."</table></form>\r\n"
."</body>\r\n";
}else{
// Get input
$habboName=$_POST['habboname'];
$emailAddress=$_POST['emailaddress'];
$reason=$_POST['reason']-1;
$reason=$reasons[$reason];
$message=$_POST['message'];
// Validate input
if($habboName==""||$emailAddress==""||$reason==""||$message=="") die("<b>You left something out...</b><br />Please go back and try again.");
if(!preg_match( "/^([a-zA-Z0-9])+([a-zA-Z0-9\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/", $emailAddress)) die("<b>Invalid email address...</b><br />Please re-type your email address and try again.");
}
// Send email
$mail=mail($emailTo,"Form Submission ({$reason})","Date: ".date("r (U)")."\r\n\r\nIP Address: {$_SERVER['REMOTE_ADDR']}\r\n\r\nHabbo Name: {$habboName}\r\n\r\nReturn email: {$emailAddress}\r\n\r\nReason: {$reason}\r\n\r\nMessage:\r\n{$message}","From: Your site");
// Success or Error
if($mail) die("<b>Message sent successfully.</b><br />Thank you for contacting us. We hope to reply within 24-48 hours.");
else die("<b>Unable to send email</b><br />Please try again later.");
?>