Need some help with file upload script

<?php
/*
    AppScene.org Upload Script
    Coded by:newhen
*/

mysql_connect("localhost", "appscene", "******");
mysql_select_db("appscene_uploads");

//ini_set("upload_tmp_dir","temp/");
//set_time_limit(0);

// upload config

$maxsize    = 106971520; // in bytes
$up_dir     = "files/"; // upload dir
$dispdir    = "files/"; // upload dir

$page_title = "AppScene - You crack it, We host it.";

$allowed    = array(
                "application/x-itunes-ipa",
                "application/octet-stream",
                "application/zip",
                "application/x-rar-compressed"
              );

$ext        = array(
                "application/x-itunes-ipa" => ".ipa",
                "application/octet-stream" => ".ipa",
                "application/zip" => ".ipa",
                "application/x-rar-compressed" => ".rar",
              );

// end config

function r() {
    $charset = "0123456789abcdefghijklmnopqrstuvwxyz";//
    $number = rand( 0, strlen($charset) );
	return $charset{$number} ? $charset{$number} : "a";
}

function newname(){
    $out = time();
    return $out;
}

function clean($clean){
    $clean = htmlentities($clean);
    return $clean;
}

function nclean($clean){
    $clean = htmlentities($clean);
    return $clean;
}

function upload(){
    global $maxsize;
    global $up_dir;
    global $dispdir;
    global $allowed;
    global $ext;

    $host      = clean($_SERVER["HTTP_HOST"]);
    $file_name = nclean($_FILES['userfile']['name']);
    $temp_name = $_FILES['userfile']['tmp_name'];
    $file_type = $_FILES['userfile']['type'];
    $file_size = $_FILES['userfile']['size'];
    $result    = $_FILES['userfile']['error'];

      //File Name Check
    if ( $file_name == "" || substr_count($file_name, ".php") ){
          $message = "<br><br>Invalid file name specified.";
          return $message;
    }
    //File Size Check
    else if ( $file_size > $maxsize) {
        $message = "<br><br>Sorry, the filesize limit is 100MB.";
        return $message;
    }
    //File Type Check
    else if ( !in_array($file_type, $allowed) ){
        $message = "<br><br>Sorry, that filetype isn't allowed." ;
        return $message;
    }
    //return "$temp_name : $outfile : <a href=\"http://$host/$outfile\">http://$host/$outfile</a><br />";


    $sqldate   = date("ymdHis");
    $ip        = clean($_SERVER["REMOTE_ADDR"]);
    $file_name = str_ireplace($ext[$file_type],"",$file_name);
    $sqlname   = mysql_real_escape_string($file_name);
    $fileoln   = str_ireplace(".", "-", $file_name);
    $newname   = newname();
    $outfile   = $up_dir.$fileoln.".$newname".$ext[$file_type]; //$newname.
    $dispfile  = $dispdir.$fileoln.".$newname".$ext[$file_type];
    $result    = move_uploaded_file($temp_name, $outfile);
                 chmod($outfile, 0755);


    $scs = "<br><br>File: <a href=\"http://$host/$dispfile\">http://$host/$dispfile</a>";
    $fal = "Somthing went wrong with upload. Try again in a few minutes.";

    if($result){
        mysql_query("INSERT INTO `files` (`id` ,`name`, `type` ,`path` ,`date` ,`ip` ) VALUES ( NULL , '$sqlname', '$file_type', '$outfile', '$sqldate', '$ip' )");
        return $scs;
    }else
        return $fal;

}

$useragent = strtolower(clean($_SERVER["HTTP_USER_AGENT"]));
if (!empty($_FILES))
$greet      = upload();
include ('header.php');
echo '<div class="outerbox">';
echo '<div class="uploadbox">';
echo '<div class="uploadbox">';
echo '<form class="form" enctype="multipart/form-data" method="POST" onSubmit="document.getElementById(\'uploading\').innerHTML = \'<br /><b>Uploading...</b>\'">';
echo '<form class="form" enctype="multipart/form-data" method="POST" onSubmit="document.getElementById(\'uploading\').innerHTML = \'<br /><b>Uploading...</b>\'">';
echo '<s>Multiple Files</s> | Max File Size: 100MB<br>';
echo '<input name="userfile" type="file" size="50" /><div id="uploading"></div>';
echo '<input name="userfile" type="file" size="50" /><div id="uploading"></div>';
echo $greet;
echo '<br><br>';
echo '<input type="image" src="/img/upload.png" value="Upload File" /></input>';
echo '</form>';
echo '</div>';
echo '<p class="tos">All files uploaded are the sole responsibility of the user. AppScene.org will not be held responsible for the actions of our users. We hold no responsibility of your files due to data loss or downtime. Please use AppScene responsibly. </p>';
include ('footer.php');
echo '</div>';
echo '</body>';
echo '</html>';