$nameErr = $lnameErr = $emailErr = $userErr = $passErr = $pass2Err = "";
  $name = $lname = $email = $user = $pass = $pass2 = "";
  if (isset($_POST['submit']) && !empty($_POST)){
    if(!empty($_POST['first_name']) || !empty($_POST['last_name']) || !empty($_POST['email']) || !empty($_POST['password']) ||
    !empty($_POST['password_repeat'])) {
      $name = mysqli_real_escape_string($db, $_POST['first_name']);
      $lname = mysqli_real_escape_string($db,  $_POST['last_name']);
      $email = mysqli_real_escape_string($db,  $_POST['email']);
      $user = mysqli_real_escape_string($db,  $_POST['user_name']);
      $pass = mysqli_real_escape_string($db,  $_POST['password']);
      $passprt = sha1($pass);
      insert($name, $lname, $email, $user, $passprt);

    } else {
      if(empty($_POST['first_name'])){
        $nameErr = 'Your first name is required!';
      }
      if(empty($_POST['last_name'])){
        $lnameErr = 'Your last name is required!';
      }
      if (empty($_POST['email'])) {
        if (!filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {
          $emailErr = "Your email format is invalid!";
        } else {
          $emailErr = "Your email address is required!";
        }
      }
      if(empty($_POST['user_name'])){
        $userErr = 'An user name is required!';
      }
      if(empty($_POST['password'])) {
        if (strlen($_POST['password']) <= '8') {
          $passErr = "Your Password Must Contain At Least 8 Characters!";
        }
        elseif(!preg_match('#[0-9]+#', $_POST['password'])) {
          $passErr = "Your Password Must Contain At Least 1 Number!";
        }
        elseif(!preg_match('#[A-Z]+#', $_POST['password'])) {
          $passErr = "Your Password Must Contain At Least 1 Capital Letter!";
        }
        elseif(!preg_match('#[a-z]+#', $_POST['password'])) {
          $passErr = "Your Password Must Contain At Least 1 Lowercase Letter!";
        } else {
          $passErr = 'A password is required!';
        }
      }
      if($_POST['password_repeat'] != $_POST['password']){
        $pass2Err = 'password did not match!';
      }
    }
  }