PHP code of Registration Form

registration-template.php

<?php

$success = '';
$error = '';
global $wpdb, $PasswordHash, $current_user, $user_ID;
 
if(isset($_POST['task']) && $_POST['task'] == 'register' ) {
	$password1 = $wpdb->escape(trim($_POST['password1']));
	$password2 = $wpdb->escape(trim($_POST['password2']));
	$first_name = $wpdb->escape(trim($_POST['first_name']));
	$last_name = $wpdb->escape(trim($_POST['last_name']));
	$email = $wpdb->escape(trim($_POST['email']));
	$username = $wpdb->escape(trim($_POST['username']));
	
	if( $email == "" || $password1 == "" || $password2 == "" || $username == "" || $first_name == "" || $last_name == "") {
		$error = 'Please don\'t leave the required fields.';
	} else if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {
		$error = 'Invalid email address.';
	} else if(email_exists($email) ) {
		$error = 'Email already exist.';
	} else if($password1 <> $password2 ){
		$error = 'Password do not match.';		
	} else {
 
		$user_id = wp_insert_user( array ('first_name' => apply_filters('pre_user_first_name', $first_name), 'last_name' => apply_filters('pre_user_last_name', $last_name), 'user_pass' => apply_filters('pre_user_user_pass', $password1), 'user_login' => apply_filters('pre_user_user_login', $username), 'user_email' => apply_filters('pre_user_user_email', $email), 'role' => 'subscriber' ) );
		if( is_wp_error($user_id) ) {
			$error = 'Error on user creation.';
		} else {
			do_action('user_register', $user_id);
			
			$success = 'You\'re successfully register';
		}
		
	}
	
}
 
?>