How to validate a connection between JS And PHP - php

Question

PHP Code:
$dom = new DOMDocument;
$headtitle = "Register";
$errors = array();
if(isset($_POST['register'])){
$username = preg_replace('/[^A-Za-z]/', '', $_POST['username']);
$name = $_POST['name'];
$lastname = $_POST['lastname'];
$email = $_POST['email'];
$password = $_POST['password'];
$c_password = $_POST['c_password'];
$birthday = $_POST['birthday'];
$country = $_POST['country'];
$gender = $_POST['gender'];
$age = $_POST['age'];
$level = $_POST['level'];
$date = $_POST['date'];
if(file_exists('users/' . $username . '.xml')){
$errors[] = ' Username already exists';
}
if($username == ''){
$errors[] = ' Username is missing. Try again.';
}
if($name == ''){
$errors[] = ' Name is missing. Try again.';
}
if($lastname == ''){
$errors[] = ' Lastname is missing. Try again.';
}
if($country == ''){
$errors[] = ' Country is missing. Try again.';
}
if($gender == ''){
$errors[] = ' Gender is missing. Try again.';
}
if($age == ''){
$errors[] = ' Age is missing. Try again.';
}
if($email == ''){
$errors[] = ' Email is missing. Try again.';
}
if($password == '' || $c_password == ''){
$errors[] = ' Passwords are missing. Try again.';
}
if($password != $c_password){
$errors[] = ' Passwords do not match';
}
if(count($errors) == 0){
$xml = new SimpleXMLElement('<user></user>');
$xml->addChild('name', ($name));
$xml->addChild('lastname', ($lastname));
$xml->addChild('password', md5($password));
$xml->addChild('birthday', $birthday);
$xml->addChild('country', $country);
$xml->addChild('gender', $gender);
$xml->addChild('age', $age);
$xml->addChild('email', $email);
$xml->addChild('level', $level);
$xml->addChild('date', $date);
$xml->asXML('users/' . $username . '.xml');
header('Location: index.php');
die;
}
}
Javascript Code:
function vaildate() {
if (document.getElementById('username').value.length <= 4) {
document.getElementById('errors').innerHTML = "Username must me more than 4 words <br />";
return false;
}
return true;
}
Now my problem is, that when I click submit button (that contains name="login" and onclick="vaildate();") he excute only php errors and ignores javascript errors (assuming that id="username" has less than 4 words).
My question is how can I make Javascript & PHP errors work? not only PHP and the system ignores Javascript.
Thank you all..
EDIT:
Also i got this code to echo PHP errors
if(count($errors) > 0){
echo '<font color="red"><ul>';
foreach($errors as $e){
echo '<li>' . $e . '</li>';
}
echo '</ul></font>';
}

Answer 1

Try this:
onclick="return vaildate();"
You need to return the validate function (return the true or false), not just call it.

Answer 2

Your Javascript and PHP you are showing looks fine. What we don't have is the actual markup of the login page. My suspicion is that your markup is not consistent with the code you have in your Javascript.
If you could also try and explain more specifically what you mean by
My question is how can I make Javascript & PHP errors work? not only PHP and the system ignores Javascript.
Have you used a Javascript debugger to see if part your Javascript (maybe elsewhere on the page) is erroring?