//Getting data from database
    func getData() -> Void {

        let url: String = "http://localhost/fridge_app/login.php" //this will be changed to the path where service.php lives

        //created NSURL
        let requestURL = NSURL(string: url)

        //creating NSMutableURLRequest
        var request = URLRequest(url: requestURL! as URL)

        //setting the method to post
        request.httpMethod = "POST"


        //Getting values from textfield
        let usernameVal = username.text
        let passwordVal = password.text

        //creating the post parameter by concatenating the keys and values from text field
        let postString = "username=(usernameVal!)&password=(passwordVal!)";
        print(postString)
        request.httpBody = postString.data(using: String.Encoding.utf8)

        //creating a task to send the post request
        let task = URLSession.shared.dataTask(with: request as URLRequest){
            data, response, error in

            //exiting if there is some error
            if error != nil{
                print("error is (error)")
                return;
            }

            // Print out response string
            var responseString: NSString?;
            responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
            if(responseString == "invalid"){
                self.isValid = false;
                print(self.isValid)
            }

            if self.checkLogin(data: responseString!) == true {
                self.performSegue(withIdentifier: "profileViewController", sender: self)
            }
            else{
                print("Hello")
                // It prints hello fine, but when it tries to run the showAlert function it fails
                self.showAlert()
            }


            //print("responseString = (self.responseString)")

        }

        //executing the task
        task.resume()
   }

/*
     * Show UIAlert Message
     */
    func showAlert() -> Void{
        let alert = UIAlertController(title: "User Does Not Exist",
                                      message: "",
                                      preferredStyle: UIAlertControllerStyle.alert)
        let loginFail = UIAlertAction(title: "Close", style: .default, handler: nil);

        alert.addAction(loginFail);
        present(alert, animated: true)

    }