objective c - sending files to server and receiving feedback -

i have code send file server:

  nsdata *data = [nsdata datawithcontentsoffile:path];     nsmutablestring *urlstring = [[nsmutablestring alloc] initwithformat:@"name=thefile&&filename=recording"];     [urlstring appendformat:@"%@", data];     nsdata *postdata = [urlstring datausingencoding:nsasciistringencoding                                allowlossyconversion:yes];     nsstring *postlength = [nsstring stringwithformat:@"%d", [postdata length]];     nsstring *baseurl = @"http://websitetester.com/here.php";      nsurl *url = [nsurl urlwithstring:baseurl];     nsmutableurlrequest *urlrequest = [nsmutableurlrequest requestwithurl:url];     [urlrequest sethttpmethod: @"post"];     [urlrequest setvalue:postlength forhttpheaderfield:@"content-length"];     [urlrequest setvalue:@"application/x-www-form-urlencoded"       forhttpheaderfield:@"content-type"];     [urlrequest sethttpbody:postdata];      nsurlconnection *connection = [nsurlconnection connectionwithrequest:urlrequest delegate:self];     [connection start];      nslog(@"file send server!"); 

this code works receive return server, php file @ end of code show:

<?php  if(...){  ...  echo "data received";  }else{  ...  echo "error in server"; }  ?> 

all i'm trying receive echo in php , show alert inside app, how code can implement inside code that?

edit  

hey find code receive return data in objetive-c, code is:

nsurlresponse* response;     nserror* error;       nsdata* result = [nsurlconnection sendsynchronousrequest:urlrequest returningresponse:&response error:&error];      nsstring *returnstring = [[nsstring alloc] initwithdata:result encoding:nsutf8stringencoding];     nslog(@"return: %@",returnstring); 

and code works way expected.