Why do I keep getting a 500 error with my PHP? - php

Question

I am trying to create an account registration page and when I add a system to check the database and make sure that there are not multiple rows with the same username, I get a 500 error.
Here's the code that works:
<?php
if(isset ($_POST['submit']))
{
include( 'connection.php' );
$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];
if(empty($username) || empty($email) || empty($password))
{
echo 'Please check the required fields.';
}
elseif(!filter_var($email,FILTER_VALIDATE_EMAIL))
{
echo 'Please enter a correct email address.';
}
else
{
$password = md5($password);
$sql = mysql_query("INSERT INTO users (email,username,password) VALUES ('$email','$username','$password')") or die(mysql_error());
if($sql)
{
echo 'Successfully submitted.';
}
}
}
?>
Here's the code that gives me a 500 error:
<?php
error_reporting(E_ALL)
if(isset ($_POST['submit'])) {
include( 'connection.php' );
$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];
$fetch = mysql_query("SELECT * FROM users WHERE username = '$email'") or die(mysql_error();
$num_rows = mysql_num_rows($fetch);
if(empty($username) || empty($email) || empty($password)) {
echo 'Please check the required fields.';
}
elseif(!filter_var($email,FILTER_VALIDATE_EMAIL)) {
echo 'Please enter a correct email address.';
}
elseif($num_rows >= 1);
{
echo 'This username is taken.';
else
}
$password = md5($password);
$sql = mysql_query("INSERT INTO users (email,username,password) VALUES ('$email','$username','$password')") or die(mysql_error());
if($sql)
{
echo 'Successfully submitted.';
}
}
}
?>

Answer 1

Maybe add a semi colon:
error_reporting(E_ALL);
EDIT:
You are also missing a ) on die(mysql_error();
Remove the ; from elseif($num_rows >= 1);
And then fix your else block to be } else {

Answer 2

You missed a semi-colon off your first statement

Answer 3

you have
else }
in your code. That's a syntax error. You're looking for
}
else {
instead.