<?php

if(isset($_POST['save'])){

$image = $_FILES['img']['name'];
$target_dir = "../blog/upload";
$target_file = $target_dir . basename($_FILES["img"]["name"]);
move_uploaded_file($_FILES['img']['tmp_name'],$target_file);

//get rid of all database operation and connection

}
?>

<form action="add_posts.php" method="POST" enctype="multipart/form-data">
<div class="form-group">
<label for="img"><span class='name'>Select Image:</span></label>
<input type="file" class="form-control" name="img" id="img"
placeholder="Image">
</div>

localhost/sensive_blog/admin_panel/add_posts.php

admin_panel
 ->otherScript.php
 ->somefolder
 ->add_post.php
blog
 ->someotherscripts.php
 ->folder