文件上传PHP不成功[关闭]

<?php

$target_path = "./" . 'data.xml';

if (move_uploaded_file('data.xml', $target_path)) {
    echo "The file  has been uploaded";
} else {
    echo "There was an error uploading the file, please try again!";

}
?>

The above PHP script doesn't seem to work. I tried sending a HTTP POST request to this link. I end up getting a BOOLEAN NO for the move_uploaded_file and yes says there is an error.

I wonder what went wrong here.

$target_path = "uploads/";

$target_path = $target_path . basename( $_FILES['uploadedfile']['name']); 

if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path))
{
echo "The file ".  basename( $_FILES['uploadedfile']['name']). 
" has been uploaded";
} 
else
{
echo "There was an error uploading the file, please try again!";
}