iOS NSURLConnection incorrect call - ios

Question

My program register users through URL-requests, but before registration there is existence userlogin or his e-mail checking in remote database. If this data not exist program should add user data in database or (if user or e-mail exist) program should return error.
I wrote this code:
- (IBAction)buttonRegister:(id)sender {
NSString *getDataURL = [NSString stringWithFormat:#"https://*********/********.php?chklogin=%#&chkemail=%#",login.text,email.text];
NSURL *url = [NSURL URLWithString:getDataURL];
NSURLRequest *theRequest = [NSURLRequest requestWithURL:url];
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection)
urlDataCheckUser = [NSMutableData data];
else NSLog(#"Connection failed!");
}
- (void) msgtitle: (NSString*) title msgtext: (NSString*) msg
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:msg delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[alert show];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[urlDataCheckUser appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *strResult = [[NSString alloc] initWithData:urlDataCheckUser encoding:NSUTF8StringEncoding];
if ([strResult isEqualToString:#"1"])
{
[self msgtitle:#"Error" msgtext:#"E-mail or Login already use!"];
}
if ([strResult isEqualToString:#""])
{
NSString *getDataURL = [NSString stringWithFormat:#"https://**********/**********.php?reglogin=%#&regemail=%#&regpass=%#",login.text,email.text,password.text];
NSURL *url = [NSURL URLWithString:getDataURL];
NSURLRequest *theRequest = [NSURLRequest requestWithURL:url];
NSURLConnection *conn =[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
theRequest = nil;
if (conn)
{
[self msgtitle:#"Success!" msgtext:#"Please login"];
}
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
UIViewController *vc = [mainStoryboard instantiateViewControllerWithIdentifier:#"loginView"];
[self presentViewController:vc animated:YES completion:nil];
}
}
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace
{
return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
[challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}
It is work, but i get message about successful registration more then once.
What is wrong?