Alex Hedley - Reachability

//http://iosameer.blogspot.co.uk/2013/01/checking-internet-connection-in-ios-apps.html
#import "Reachability.h"

//// Just use it ,Where you need it  (checking internet connection)
Reachability *reachTest = [Reachability reachabilityWithHostName:@"www.apple.com"];
NetworkStatus internetStatus = [reachTest  currentReachabilityStatus];

if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN)) {
  /// Create an alert if connection doesn't work,no internet connection
  UIAlertView *myAlert = [[UIAlertView alloc] initWithTitle:@"No Internet Connection"
                                              message:@"You require an internet connection via WiFi or cellular network for location finding to work."
                                              delegate:self
                                              cancelButtonTitle:@"Ok"
                                              otherButtonTitles:nil];
  [myAlert show];
  [myAlert release];
}
else {
  // There is a internet connection
  /// Do,Whatever you want
}

//https://developer.apple.com/library/ios/samplecode/Reachability/Introduction/Intro.html //https://github.com/tonymillion/Reachability //http://code.tutsplus.com/tutorials/ios-sdk-detecting-network-changes-with-reachability--mobile-18299

Links

https://github.com/tonymillion/Reachability

https://developer.apple.com/library/ios/samplecode/Reachability/Introduction/Intro.html

http://code.tutsplus.com/tutorials/ios-sdk-detecting-network-changes-with-reachability--mobile-18299