<?php
require('config.php');
    function doesUsernameExist($name){
        $exit = FALSE;
        $result = @mssql_query("SELECT * FROM ACCOUNT_TBL WHERE account='$name'");
        if (mssql_num_rows($result) != 0){
            $exit = TRUE;
        }
        return $exit;
    }

    if(isset($_POST['submit'])){
        $user = preg_replace ("[^A-Za-z0-9]", "", $_POST['username']);
        $pass = preg_replace ("[^A-Za-z0-9]", "", $_POST['password']);
        if($_POST['username'] == ""){
            echo 'Please enter a username.';
        }
        else if($_POST['password'] == ""){
            echo 'Please enter a password.';
        }
        else if ((strlen($_POST['username']) > 16) || (strlen($_POST['username']) < 3)){
            echo 'The username should be 3 to 16 characters.';
        }
        else if ((strlen($_POST['password']) > 16) || (strlen($_POST['password']) < 3)){
            echo 'The password should be 3 to 16 characters.';
        }
        else if($_POST['username'] != $user){
            echo 'Please choose another username.';
        }
        else if($_POST['password'] != $pass){
            echo 'Please choose another password.';
        }
        else {
            $pass = md5('serus' . $pass);
            if(!doesUsernameExist($user)){
                $stmt = mssql_init('usp_CreateAccount', $link);
                mssql_bind($stmt, '@account', $user, SQLVARCHAR, false, false, 15);
                mssql_bind($stmt, '@password', $pass, SQLVARCHAR, false, false, 36);
                mssql_execute($stmt) or die ("Something is wrong on the execution");
                mssql_free_statement($stmt);
                echo 'Congratulations! You have successfully registered an account.';
            }
            else {
                echo 'Username already exist.';
            }
        }
        mssql_close();
    }

    echo '<form action="#" method="post">';
    echo 'Username: <input type="text" name="username" /><br />';
    echo 'Password: <input type="password" name="password" /><br />';
    echo '<input type="submit" name="submit" value="Register" />';
    echo '</form>';

?>