Miért nem jó a PHP kódban a = jel?

<?php

$nameErr = $emailErr = $usernameErr = passwordErr = $repasswordErr = "";

if(isset($_POST['name']) && !empty($_POST['name'])) {

$name=$_POST['name'];

}else {

echo "Adj meg egy nevet!";

}

if(isset($_POST['email']) && !empty($_POST['email'])) {

$email=$_POST['email'];

}else {

}

if(isset($_POST['username']) && !empty($_POST['username'])) {

$username=$_POST['username'];

}else {

}

if(isset($_POST['password']) && !empty($_POST['password'])) {

$password=$_POST['password'];

}else {

}

if(isset($_POST['repassword']) && !empty($_POST['repassword'])) {

$repassword=$_POST['repassword'];

}else {

}

?>