Parse error: syntax error, unexpected variable "$user_id"

Hi i am a php newbie and i am currently following a tutorial on how to make an login system and i am still at the login screen. Since i am new to php i don't know much about it. I hope someone expert can help me solve this problem. Here is the code

<?php
session_start();

include("connection.php");
include("functions.php");


    if($_SERVER['REQUEST_METHOD'] == "POST");
    {
        //something was posted
        $user_name = $_POST['user_name'];
        $password = $_POST['password'];

        if(!empty($user_name) && !empty($password) && !is_numeric($user_name));
        {
            //save to database
            $user_id = random_num(20);
            $query = "insert into users (user_id, user_name, password) values ("$user_id", "$user_name", "$password")";
            mysqli_query($query);

            header("location: login.php");
            die;
        } else
        {
            echo "Please enter some valid information!";
            die;
        }
    }
?>


<input id="text" type="text" name="user_name">
<input id="text" type="password" name="password">
<input id="button" type="submit" value="signup">