Ios WEb Service Communication

I am calling this test webservice and it is working fine.
<?php

header('Content-type: application/json');
if($_POST) {
    if($_POST['email'] == 'saad.bsit@hotmail.com' && $_POST['password'] == '12345') {
    echo '{"success":1}';
 } else {
    echo '{"success":0,"error_message":"Username and/or password is invalid."}';
}
}else {    echo '{"success":0,"error_message":"Username and/or password is invalid."}';}
?>

action on button in sign in page
- (IBAction)btnSignIn:(id)sender {
  @try {

        if([[txtUserEmail text] isEqualToString:@""] || [[txtUserPassword text] isEqualToString:@""] ) {
            [self alertStatus:@"Please enter both Username and Password" :@"Login Failed!"];
        } else {
            NSString *post =[[NSString alloc] initWithFormat:@"email=%@&password=%@",[txtUserEmail text],[txtUserPassword text]];
            NSLog(@"PostData: %@",post);

            NSURL *url=[NSURL URLWithString:@"http://localhost/colorSearch/sample_code.php"];

            NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

            NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

            NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
            [request setURL:url];
            [request setHTTPMethod:@"POST"];
            [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
            [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
            [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
            [request setHTTPBody:postData];

            //[NSURLRequest setAllowsAnyHTTPSCertificate:YES forHost:[url host]];

            NSError *error = [[NSError alloc] init];
            NSHTTPURLResponse *response = nil;
            NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

            NSLog(@"Response code: %d", [response statusCode]);
            if ([response statusCode] >=200 && [response statusCode] <300)
            {
                NSString *responseData = [[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding];
                NSLog(@"Response ==> %@", responseData);

                SBJsonParser *jsonParser = [SBJsonParser new];
                NSDictionary *jsonData = (NSDictionary *) [jsonParser objectWithString:responseData error:nil];
                NSLog(@"%@",jsonData);
                NSInteger success = [(NSNumber *) [jsonData objectForKey:@"success"] integerValue];
                NSLog(@"%d",success);
                if(success == 1)
                {
                    NSLog(@"Login SUCCESS");
                    [self alertStatus:@"Logged in Successfully." :@"Login Success!"];
                           ColorPickerViewController *cpvc =[[ColorPickerViewController alloc] init];
                           [self.navigationController pushViewController:cpvc animated:YES];

                } else {

                    NSString *error_msg = (NSString *) [jsonData objectForKey:@"error_message"];
                    [self alertStatus:error_msg :@"Login Failed!"];
                }

            } else {
                if (error) NSLog(@"Error: %@", error);
                [self alertStatus:@"Connection Failed" :@"Login Failed!"];
            }
        }
    }
    @catch (NSException * e) {
        NSLog(@"Exception: %@", e);
        [self alertStatus:@"Login Failed." :@"Login Failed!"];
    }




}
- (void) alertStatus:(NSString *)msg :(NSString *)title
{
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title
                                                        message:msg
                                                       delegate:self
                                              cancelButtonTitle:@"Ok"
                                              otherButtonTitles:nil, nil];

    [alertView show];
}

But if I try this which is the actual one code execute nahi hota...I think k web service ko proper UrlRequest nahi ja rahi...This web service is working on tags,mera friend same android pa use ker raha ha and uska kaam chal raha ha...

Actual Web-service


<?php

/**
PHP API for Login, Register, Changepassword, Resetpassword Requests and for Email Notifications.
**/

if (isset($_POST['tag']) && $_POST['tag'] != '') {
   // Get tag
   $tag = $_POST['tag'];

   // Include Database handler
   require_once 'include/DB_Functions.php';
   $db = new DB_Functions();
   // response Array
   $response = array("tag" => $tag, "success" => 0, "error" => 0);

   // check for tag type
   if ($tag == 'login') {
       // Request type is check Login
       $email = $_POST['email'];
       $password = $_POST['password'];

       // check for user
       $user = $db->getUserByEmailAndPassword($email, $password);
       if ($user != false) {
           // user found
            echo '{"success":1}';
           // echo json with success = 1
           $response["success"] = 1;
           $response["user"]["fname"] = $user["firstname"];
           $response["user"]["lname"] = $user["lastname"];
           $response["user"]["email"] = $user["email"];
   $response["user"]["uname"] = $user["username"];
           $response["user"]["uid"] = $user["unique_id"];
           $response["user"]["created_at"] = $user["created_at"];

           echo json_encode($response);
       } else {
           // user not found
           // echo json with error = 1
           $response["error"] = 1;
           $response["error_msg"] = "Incorrect email or password!";
           echo json_encode($response);
           echo '{"success":0,"error_message":"Username and/or password is invalid."}';
       }
   }
 else if ($tag == 'chgpass'){
 $email = $_POST['email'];

 $newpassword = $_POST['newpas'];


 $hash = $db->hashSSHA($newpassword);
       $encrypted_password = $hash["encrypted"]; // encrypted password
       $salt = $hash["salt"];
 $subject = "Change Password Notification";
        $message = "Hello User,\n\nYour Password is sucessfully changed.\n\nRegards,\nDigitalnet Team.";
         $from = "contact@Digitalnet.com";
         $headers = "From:" . $from;
if ($db->isUserExisted($email)) {

$user = $db->forgotPassword($email, $encrypted_password, $salt);
if ($user) {
        $response["success"] = 1;
         mail($email,$subject,$message,$headers);
        echo json_encode($response);
}
else {
$response["error"] = 1;
echo json_encode($response);
}


           // user is already existed - error response


       }
          else {

           $response["error"] = 2;
           $response["error_msg"] = "User not exist";
            echo json_encode($response);

}
}
else if ($tag == 'forpass'){
$forgotpassword = $_POST['forgotpassword'];

$randomcode = $db->random_string();


$hash = $db->hashSSHA($randomcode);
       $encrypted_password = $hash["encrypted"]; // encrypted password
       $salt = $hash["salt"];
 $subject = "Password Recovery";
        $message = "Hello User,\n\nYour Password is sucessfully changed. Your new Password is $randomcode . Login with your new Password and change it in the User Panel.\n\nRegards,\nLearn2Crack Team.";
         $from = "contact@Digitalnet.com";
         $headers = "From:" . $from;
if ($db->isUserExisted($forgotpassword)) {

$user = $db->forgotPassword($forgotpassword, $encrypted_password, $salt);
if ($user) {
        $response["success"] = 1;
         mail($forgotpassword,$subject,$message,$headers);
        echo json_encode($response);
}
else {
$response["error"] = 1;
echo json_encode($response);
}


           // user is already existed - error response


       }
          else {

           $response["error"] = 2;
           $response["error_msg"] = "User not exist";
            echo json_encode($response);
              echo '{"success":0,"error_message":"Username and/or password is invalid."}';

}

}
else if ($tag == 'register') {
       // Request type is Register new user
       $fname = $_POST['fname'];
$lname = $_POST['lname'];
       $email = $_POST['email'];
$uname = $_POST['uname'];
       $password = $_POST['password'];



         $subject = "Registration";
        $message = "Hello $fname,\n\nYou have sucessfully registered to our service.\n\nRegards,\nAdmin.";
         $from = "contact@Digitalnet.com";
         $headers = "From:" . $from;

       // check if user is already existed
       if ($db->isUserExisted($email)) {
           // user is already existed - error response
           $response["error"] = 2;
           $response["error_msg"] = "User already existed";
           echo json_encode($response);
       }
          else if(!$db->validEmail($email)){
           $response["error"] = 3;
           $response["error_msg"] = "Invalid Email Id";
           echo json_encode($response);
}
else {
           // store user
           $user = $db->storeUser($fname, $lname, $email, $uname, $password);
           if ($user) {
               // user stored successfully
           $response["success"] = 1;
           $response["user"]["fname"] = $user["firstname"];
           $response["user"]["lname"] = $user["lastname"];
           $response["user"]["email"] = $user["email"];
   $response["user"]["uname"] = $user["username"];
           $response["user"]["uid"] = $user["unique_id"];
           $response["user"]["created_at"] = $user["created_at"];
              mail($email,$subject,$message,$headers);

               echo json_encode($response);
           } else {
               // user failed to store
               $response["error"] = 1;
               $response["error_msg"] = "JSON Error occured in Registartion";
               echo json_encode($response);
           }
       }
   } else {
        $response["error"] = 3;
        $response["error_msg"] = "JSON ERROR";
       echo json_encode($response);
   }
} else {
   echo "Digitalnet API";
}
?>