Log in:
<form method=POST action=login.php>
	Username: <input name=existingusername><br>
	Password: <input type=password name=pass><br>
	<input type=submit value='Login'>
</form>
Or create a new account:
<form method=POST action=login.php>
	Username: <input name=newusername maxlength=50><br>
	Password: <input type=password name=pwd maxlength=900> (stored as salted sha256)<br>
	Repeat password: <input type=password name=pwd2> (optional, but if you enter this then it will be checked)<br>
	<input type=submit value='Create account'>
</form>