Custom EE Dropbox upload form

Dropboxuploader.php

<?php
if ($_POST) {
	
	require CUSTOM_SCRIPTS_FOLDER.'dropboxuploader.php';
	
	try {
		// Rename uploaded file to reflect original name
		if ($_FILES['file']['error'] !== UPLOAD_ERR_OK)
			throw new Exception('File was not successfully uploaded from your computer.');

		$tmpDir = uniqid('/tmp/DropboxUploader-');
		if (!mkdir($tmpDir))
			throw new Exception('Cannot create temporary directory!');

		if ($_FILES['file']['name'] === "")
			throw new Exception('File name not supplied by the browser.');

		$tmpFile = $tmpDir.'/'.str_replace("/\0", '_', $_FILES['file']['name']);
		if (!move_uploaded_file($_FILES['file']['tmp_name'], $tmpFile))
			throw new Exception('Cannot rename uploaded file!');

		// Upload
		$uploader = new DropboxUploader('[email protected]', 'password');
		$uploader->upload($tmpFile, 'client_files/'.$_POST['dest']);
		
		$this->EE->load->library('email'); 					

		// $this->EE->email->initialize($config);					

		$this->EE->email->from($this->EE->input->post('email'), $this->EE->input->post('name'));
		$this->EE->email->to('[email protected]'); 
		//$this->EE->email->cc('[email protected]'); 
		//$this->EE->email->bcc('[email protected]'); 
		
		$filename = $_FILES['file']['name'];
		
		//echo var_dump($_FILES['file']['name']);
			
		$this->EE->email->subject('File uploaded to your Dropbox');
		$this->EE->email->message('A new file has been uploaded to your Dropbox.'."\n\n".
		'Filename: '.
		$filename . "\n\n" .
		'Destination: '.
		$this->EE->input->post('dest') . "\n\n" . 
		'Additional Instructions: '.
		$this->EE->input->post('notes') . "\n\n"					
		
		);	

		$this->EE->email->send();					
		$this->EE->functions->redirect('/success');
		//echo $this->EE->email->print_debugger();
				
		
		echo '<span style="color: green">Thanks your file has successfully been uploaded to our server!</span>';
	} catch(Exception $e) {
		echo '<span style="color: red">Error: ' . htmlspecialchars($e->getMessage()) . '</span>';
	}

	// Clean up
	if (isset($tmpFile) && file_exists($tmpFile))
		unlink($tmpFile);

	if (isset($tmpDir) && file_exists($tmpDir))
		rmdir($tmpDir);
}
?>
<form method="post" enctype="multipart/form-data">


<div class="form-field"><label>Destination directory (optional)</label><input type="text" name="dest" /> <p class="field-notes">e.g. "company name/project", will be created if it doesn't exist</p></div>
<div class="form-field"><label>File</label><input type="file" name="file" /></div>

<div class="form-field"><label>Your name</label> <input type="text" name="name" /></div>
<div class="form-field"><label>Your email address</label> <input type="email" name="email" /></div>
<div class="form-field"><label>Additional notes:</label><textarea name="notes"></textarea></div>
<div><input type="submit" name="submit" value="Upload file now" /></div>
</form>