javascript Form validation Source code

Today, We want to share with you javascript Form validation Source code.In this post we will show you javascript form validation library, hear for javascript form validation example download we will give you demo and example for implement.In this post, we will learn about student registration form in html with javascript validation with an example.

javascript Form validation Source code

There are the Following The simple About javascript Form validation Source code Full Information With Example and source code.

As I will cover this Post with live Working example to develop JavaScript : A sample registration form validation, so Form validation using HTML and JavaScript for this example is following below.

Step 1:


<!DOCTYPE html>
<html lang="en">
  <meta charset="UTF-8">
  <title>Form validation with JavaScript -</title>
  <link rel="stylesheet" href="style.css">
  <div id="wrapper">
   <form method="POST" action="index.php" onsubmit="return Validate()" name="signup_Form" >
   	<div id="user_name_area">
   	  <label>Username</label> <br>
   	  <input type="text" name="userFullName" class="textInput">
   	  <div id="name_error"></div>
   	<div id="user_email_address_area">
   	  <label>Email</label> <br>
   	  <input type="email" name="email" class="textInput">
   	  <div id="email_error"></div>
   	<div id="user_pass_area">
   	  <label>Password</label> <br>
   	  <input type="password" name="password" class="textInput">
   	<div id="user_pass_confirm_area">
   	   <label>Password confirm</label> <br>
   	   <input type="password" name="repeat_confirm_pass" class="textInput">
   	   <div id="preview_pass_err"></div>
   	<input type="submit" name="register" value="Register" class="btn">
<script type="main.js"></script>

Step 2 : Custom CSS Part


#wrapper {
  width: 30%;
  margin: 50px auto;
  padding: 50px;
  background: #D7FBFF;
form {
  margin: 30px auto;
.textInput {
  border: none;
  height: 28px;
  margin: 2px;
  border: 1px solid #6B7363;
  font-size: 1.2em;
  padding: 5px;
  width: 95%;
.textInput:focus {
  outline: none;
.btn {
  width: 98.6%;
  border: none;
  margin-top: 5px;
  color: white;
  background-color: #3b5998;
  border-radius: 5px;
  padding: 12px;

Step : 3 JavaScript Source code

JavaScript Functions(main.js)

var userFullName = document.forms['signup_Form']['userFullName'];
var email = document.forms['signup_Form']['email'];
var password = document.forms['signup_Form']['password'];
var repeat_confirm_pass = document.forms['signup_Form']['repeat_confirm_pass'];
var name_error = document.getElementById('name_error');
var email_error = document.getElementById('email_error');
var preview_pass_err = document.getElementById('preview_pass_err');
userFullName.addEventListener('blur', nameVerify, true);
email.addEventListener('blur', checkEmailAddress, true);
password.addEventListener('blur', checkPassword, true);
// validation function
function Validate() {
  // validate userFullName
  if (userFullName.value == "") { = "1px solid red";
    document.getElementById('user_name_area').style.color = "red";
    name_error.textContent = "Username is required";
    return false;
  // validate userFullName
  if (userFullName.value.length < 3) { = "1px solid red";
    document.getElementById('user_name_area').style.color = "red";
    name_error.textContent = "Username must be at least 3 characters";
    return false;
  // validate email
  if (email.value == "") { = "1px solid red";
    document.getElementById('user_email_address_area').style.color = "red";
    email_error.textContent = "Email is required";
    return false;
  // validate password
  if (password.value == "") { = "1px solid red";
    document.getElementById('user_pass_area').style.color = "red"; = "1px solid red";
    preview_pass_err.textContent = "Password is required";
    return false;
  // check if the two passwords match
  if (password.value != repeat_confirm_pass.value) { = "1px solid red";
    document.getElementById('user_pass_confirm_area').style.color = "red"; = "1px solid red";
    preview_pass_err.innerHTML = "The two passwords do not match";
    return false;
// event handler functions
function nameVerify() {
  if (userFullName.value != "") { = "1px solid #ce0000";
   document.getElementById('user_name_area').style.color = "#ce0000";
   name_error.innerHTML = "";
   return true;
function checkEmailAddress() {
  if (email.value != "") { = "1px solid #ce0000";
  	document.getElementById('user_email_address_area').style.color = "#ce0000";
  	email_error.innerHTML = "";
  	return true;
function checkPassword() {
  if (password.value != "") { = "1px solid #ce0000";
  	document.getElementById('user_pass_confirm_area').style.color = "#ce0000";
  	document.getElementById('user_pass_area').style.color = "#ce0000";
  	preview_pass_err.innerHTML = "";
  	return true;
  if (password.value === repeat_confirm_pass.value) { = "1px solid #ce0000";
  	document.getElementById('user_pass_confirm_area').style.color = "#ce0000";
  	preview_pass_err.innerHTML = "";
  	return true;

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