How to get distance between two location in iphone sdk

// .h

CLLocationManager *locationManager;

//

//ViewDidLoad

locationManager.delegate = self;

locationManager.desiredAccuracy = kCLLocationAccuracyBest ;

[locationManager startUpdatingLocation];

//

// delegate start here

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation

{

CLLocationCoordinate2D loc = [newLocation coordinate];

str1 = [NSString stringWithFormat: @"%.10f", loc.latitude];

NSLog(@"str1 %@",str1);

str2 = [NSString stringWithFormat: @"%.10f", loc.longitude];

NSLog(@"str2 %@",str2);

NSString *strsitename=[[arraySiteNameOnly objectAtIndex:0]objectForKey:@"Site_name"];

NSString *strlatitude = [[arrayLatitiude objectAtIndex:0]objectForKey:@"Latitude"];

NSString *finalLati = [strlatitude stringByReplacingOccurrencesOfString:@"N" withString:@"+"];

finalLati = [finalLati stringByReplacingOccurrencesOfString:@"S" withString:@"-"];

NSString *strllongitude = [[arrayLongitude objectAtIndex:arrayindex]objectForKey:@"Longitude"];

NSString *finalLongi = [strllongitude stringByReplacingOccurrencesOfString:@"E" withString:@"+"];

finalLongi = [finalLongi stringByReplacingOccurrencesOfString:@"W" withString:@"-"];

float distLatitude = 69.1 * ([finalLati floatValue] - [str1 floatValue]);

float disLongitude = 69.1 * ([finalLongi floatValue] - [str2 floatValue]) * cos([str1 floatValue]/57.3);

float distance= sqrt(distLatitude * distLatitude + disLongitude * disLongitude);

[locationManager stopUpdatingLocation];

}