request.m

 NSMutableURLRequest *request;
    NSError *error;
    NSURLResponse* response;
    NSData *receivedData;
    NSString*result;
static NSString* url_pic =@"http://douban.fm/misc/captcha?size=m&id=";
    request=[NSMutableURLRequest requestWithURL:[NSURL URLWithString:url_fav_song]];
    [request setValue:@"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" forHTTPHeaderField:@"Accept"];
    [request setValue:@"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:11.0) Gecko/20100101 Firefox/11.0" forHTTPHeaderField:@"User-Agent"];
    receivedData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    if (receivedData) {  
            
        result=[[NSString alloc]initWithData:receivedData encoding:NSUTF8StringEncoding];
        
    } else {  
        // Inform the user that the connection failed.  
    }  
    NSLog(@"receive data: %@",result);