WWW form doesn't work only on andriod

I'm making a scoreboard for my game, and I built my server and db.

I'm using this code and it works fine on PC.

 IEnumerator PostScores(string name, int score)
 {
     string hash = Md5Sum(name + score + secretKey);

     string post_url = addScoreURL + "name=" + name + "&score=" + score +     "&hash=" + hash;

     WWW hs_post = new WWW("http://"+post_url);

     yield return hs_post; 

     if (hs_post.error != null)
     {
         print("There was an error posting the high score: " +     hs_post.error);
     }
 }

And this is my php

 <?php 
     $db = mysql_connect('mysql.hostinger.kr', 'name', 'ps') or die('Could not connect: ' . mysql_error()); 
     mysql_select_db('dbname') or die('Could not select database');

     $name = mysql_real_escape_string($_GET['name'], $db); 
     $score = mysql_real_escape_string($_GET['score'], $db); 
     $hash = $_GET['hash']; 
 
     $secretKey="key"; 

     $real_hash = md5($name . $score . $secretKey); 
     if($real_hash == $hash) { 
         $query = "insert into scores values (NULL, '$name', '$score');"; 
         $result = mysql_query($query) or die('Query failed: ' . mysql_error()); 
     } 
 ?>

On android, my app doesn't upload data to the db.. I don't know why. please help me