/* ---------------------------- */
/* XMLHTTPRequest Enable */
/* ---------------------------- */
function createObject() {
    var request_type;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        request_type = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        request_type = new XMLHttpRequest();
    }
    return request_type;
}

var http = createObject();

/* -------------------------- */
/* LOGIN */
/* -------------------------- */
/* Required: var nocache is a random number to add to request. This value solve an Internet Explorer cache issue */
var nocache = 0;
function login() {
    // Optional: Show a waiting message in the layer with ID ajax_response
    document.getElementById('login_response').innerHTML = "Loading..."
    // Required: verify that all fileds is not empty. Use encodeURI() to solve some issues about character encoding.
    var user = encodeURI(document.getElementById('loginuser').value);
    var psw = encodeURI(document.getElementById('loginpass').value);
    // Set te random number to add to URL request
    nocache = Math.random();
    // Pass the login variables like URL variable
    http.open('get', 'logincheck.php?user='+user+'&pass='+psw+'&nocache = '+nocache);
    http.onreadystatechange = loginReply;
    http.send(null);
}

function loginReply() {
    if(http.readyState == 4){
        var response = http.responseText;
        if (response === false){
            // if login fails
            document.getElementById('login_response').innerHTML = '<div class="alert"><strong>Warning!</strong> Looks like you entered something wrong!.</div>';
        // else if login is ok show a message: "Welcome + the user name".
        } else {
            document.getElementById('login_response').innerHTML = '<div class="alert alert-success"><strong>Hey!</strong> Welcome back, ' + response + '</div>';
        }
    }
}