NSError *error = nil;
// assign the cmh url from user prefs
NSURL *url = [NSURL URLWithString:cmhUrl];

// Put that URL into an NSURLRequest
NSURLRequest *req = [NSURLRequest requestWithURL:url];

[req setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];

// Create a connection that will exchange this request for data from the URL
connection = [[NSURLConnection alloc] initWithRequest:req
                                             delegate:self
                                     startImmediately:YES];