通过HTTP链接从UITextField发送UTF8字符串

Question

I'm using php method as web service to add user_comment to mysql database.

 <?php 
    require '../database/connection.php'; 
    extract($_POST);

    if (isset($_GET['book_ID'])) {

        $book_ID = $_GET['book_ID'];
        $user_ID = $_GET['user_ID'];
        $theComment = $_GET['theComment'];
    }

if (!$db) {

    $json[] = array("Message" => "Connection failed");
    echo json_encode($json);
}

$sql = mysql_query("INSERT INTO Comment (user_ID , book_ID , theComment) VALUES ('$user_ID','$book_ID','$theComment')");
mysql_query($sql, $db);

$json[] = array("Message" => "Done");
echo json_encode($json);

everything fine if I type English but I have problem with Arabic

Objective-C:

-(NSString *)addCommentForBook:(NSString *)bookID userID:(NSString *)userID theComment:(NSString *)theComment{
    NSString *dt = [NSString stringWithFormat:@"?book_ID=%@&user_ID=%@&theComment=%@",bookID,userID,theComment];
    NSURL *myURL = [[NSURL alloc]initWithString:[NSString stringWithFormat:@"http://www.myweb.com/library/Books/addCommentForBook.php%@",dt]];
    NSMutableDictionary *theArray;
    NSData *myData = [[NSData alloc]initWithContentsOfURL:myURL];

    if (myData) {
        id myJSON = [NSJSONSerialization JSONObjectWithData:myData options:NSJSONReadingMutableContainers error:nil];
        theArray = (NSMutableDictionary *)myJSON;
    }

    return [[theArray valueForKey:@"Message"]objectAtIndex:0];
}

If I test from Browser work php work fine with Arabic but from iOS not work

Any one tell me what's wrong or do I need to convert the string from UITextField first or?