title: NSCFString absoluteURL exception
body: <p>This is my code to retrieve data from a MySQL table using JSON:</p>
  
  <pre><code>//URL definition where php file is hosted
  
      int categoriaID = [[categoriaDescription objectForKey:@"idCategoria"] intValue];
  
      NSString *string = [NSString stringWithFormat:@"%d", categoriaID];
      NSLog(@"CATEGORIA ID STRING %@",string);
      NSMutableString *ms = [[NSMutableString alloc] initWithString:@"http://mujercanariasigloxxi.appgestion.eu/app_php_files/categoriaslist.php?id="];
      [ms appendString:string];
      // URL request
      NSLog(@"URL = %@",ms);
      NSURLRequest *request = [NSURLRequest requestWithURL:ms];
      //URL connection to the internet
      [[NSURLConnection alloc]initWithRequest:request delegate:self];
  </code></pre>
  
  <p>The URL logged is correct, but the app throws an exception:</p>
  
  <pre><code>*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString absoluteURL]: unrecognized selector sent to instance 
  </code></pre>
  
  <p>I guess the error should be in the above code, but I don't see why. Any help is welcome.</p>