Ajax Login Plugin : IE Javascript Error

I’ve installed the Ajax login plugin on 2.3.3 and it works GREAT in Firefox, does exactly what it’s supposed to do. However – the javascript is pulling errors in IE – does anyone know enough about this to offer a fix?

The errors:
al_registerForm.user_login is null or not an object
al_loginForm.log is null or not an object

from the JS:

function al_showRegister2() {

document.getElementById("al_loading").style.display = "none";
	document.getElementById("al_register").style.display = "block";

	al_registerForm.user_login.focus();
}

function al_login() {

	if (0 != al_status) {
		return;
	}

	if (al_loginForm.log.value == '') {
		alert("Please enter username.");
		al_loginForm.log.focus();
		return;
	}

	if (al_loginForm.pwd.value == '') {
		alert("Please enter password.");
		al_loginForm.pwd.focus();
		return;
	}

	al_sack.setVar("log", al_loginForm.log.value);
	al_sack.setVar("pwd", al_loginForm.pwd.value);
	al_sack.setVar("rememberme", al_loginForm.rememberme.value);

	al_sack.requestFile = al_base_uri + "/wp-content/plugins/ajax-login/login.php";
	al_sack.method = "POST";
	al_sack.onError = al_ajaxError;
	al_sack.onCompletion = al_loginHandleResponse;
	al_sack.runAJAX();
	al_status = 1;

}