php - PHP サーバーへの画像のアップロード

Question

-(IBAction)TakePhoto{
    picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    [picker setSourceType:UIImagePickerControllerSourceTypeCamera];
    [self presentViewController:picker animated:YES completion:NULL];
    [picker release];

}

-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    image = [info objectForKey:UIImagePickerControllerOriginalImage];
    [imageView setImage:image];
    [self dismissViewControllerAnimated:YES completion:NULL];

}
-(IBAction)uploadImage{
    NSData *imageData = UIImageJPEGRepresentation(image, 90);
    NSString *urlString = @"http://myserverdomain.com/upload.php";

    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
    [request setURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"POST"];

    NSString *boundary = @"---------------------------14737809831466499882746641449"
    ;
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
    [request addValue:contentType forHTTPHeaderField: @"Content-Type"];

    NSMutableData *body = [NSMutableData data];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"Content-Disposition: form-data; name=\"userfile\"; filename=\"ipodfile.jpg\"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[NSData dataWithData:imageData]];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [request setHTTPBody:body];

    NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
    NSLog(@"heyo");

}

ここで、サーバーに画像をアップロードしようとしていますが、画像が "Pictures" フォルダーに表示されません。また、「未使用の変数 returnString」という警告が表示されます

ここに私のphpスクリプトがあります

<?php
$msg = " ".var_dump($_FILES)." ";
$new_image_name = $_FILES["file"]["name"];
move_uploaded_file($_FILES["file"]["tmp_name"], getcwd() . "/pictures/" . $new_image_name);

?>