function checkLogin(f) {
	if (!checkText(f.username, "Username")) {
		return false;
	}
	if (!checkText(f.password, "Password")) {
		return false;
	}
	if (f.username.value == "username") {
		f.username.value='';
		f.password.value='';
		alert("Please enter your username and password.");
		f.username.focus();
		return false;
	}
	return true;
}
function clearFields() {
	f = document.f1;
	if (f.username.value == 'username' && f.password.value == 'password') {
		f.username.value='';
		f.password.value='';
	}
}