var loginHandlerId = 1;

function doLogin(username,password) {

	changeOpac(0, 'errorContainer');

	var parameters = 'username=' + username.value + '&password=' + password.value + '&a=l';
	var url = 'fetch.php';

	sendAjax('POST', url, true, parameters, handleLogin, loginHandlerId);

}

function handleLogin() {

	if (http[loginHandlerId] != null && http[loginHandlerId].readyState == 4 && http[loginHandlerId].status == 200) {

		var response = http[loginHandlerId].responseText;
		var res = JSON.parse(response);

		if (res.success) {

			//javascript redirect
			window.location = res.url;

		} else {

			var feedbackDiv = document.getElementById('errorMessage');
			feedbackDiv.innerHTML = res.feedback;

			fadeIn('errorContainer');

		}

		clearHttp(loginHandlerId);
	}

}