使用Xcode 6和PHP文件将图像上传到服务器

我正试图根据用户的选择将图像发送到我的网站，每次应用程序都应该给出用户选择的图像名称。

我正在使用Xcode 6和下面的代码：

 NSString *urlString = @"http://MyWebSite.com/sendImages.php";
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"POST"];
    NSMutableData *body = [NSMutableData data];
    NSString *boundary = @"---------------------------14737809831466499882746641449";
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
    [request addValue:contentType forHTTPHeaderField:@"Content-Type"];
    // file
    NSData *imageData = UIImageJPEGRepresentation(self.imageView.image,90);
    [body appendData:[[NSString stringWithFormat:@"--%@'r'n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"Content-Disposition: attachment; name='"userfile'"; filename='"myImage.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:[@"'r'n" dataUsingEncoding:NSUTF8StringEncoding]];
    // close form
    [body appendData:[[NSString stringWithFormat:@"--%@--'r'n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    // set request body
    [request setHTTPBody:body];
    //return and test
    NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Success" message:returnString delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil];
    [alert show];

她是我的PHP文件：

<? 
    $myparam = $_FILES['userfile']; //getting image Here //getting textLabe Here 
    $target_path = "khadamati/";
    if(move_uploaded_file($myparam['tmp_name'], $target_path . basename( $myparam['name'])))
    { echo "The file ". basename( $myparam['name']). " has been uploaded"; } 
    else 
    { echo "There was an error uploading the file, please try again!"; } 
    ?>

如何更改此行中的myImage名称：

[body appendData:[@"Content-Disposition: attachment; name='"userfile'"; filename='"myImage.jpg'"'r'n" dataUsingEncoding:NSUTF8StringEncoding]];

我试着找到任何对我有帮助的薄，但我找不到，所以请在我的展位代码中找到错误。