sending a post variable to php

Hi. First post here.

ive been trying to send a variable over to php using $_post.

On button click ajax

"Email=email@hotmail.com" & TextBox.TEXT

Sent to $_POST ['email']

Echo "true"

The "true" should be sent to the lastdata variable but it doesnt seem to be going. The php script works but I think I must be missing something

Is there no one who can help?

My code works fine in Android, but doesn't work in HTML5

File upload.php

<?php

//chdir('');

$img = $_POST['photo'];

define('UPLOAD_DIR', 'user_photo/');

$img = str_replace('data:image/png;base64,', '', $img);

$img = str_replace(' ', '+', $img);

$data = base64_decode($img);

$file = UPLOAD_DIR . uniqid() . '.png';

$success = file_put_contents($file, $data);

echo $file;

?>