file upload not working

[eluser]learning_php[/eluser]
Hi,

i added to the upload view:

Code:

<?PHP
if(isset($error)){
    echo $error;
}else{
    redirect('images');
}
$data = 'Some file data';

if ( ! write_file('./wedding-site/assets/upload/', $data))
{
     echo 'Unable to write the file';
}
else
{
     echo 'File written!';
}


?>

and now it displays The upload path does not appear to be valid.
Unable to write the file