XMLHttpRequest use, works only if url is on same site.
checklogin.php give <KO/> if login è fails
<OK>XXX</OK> with XXX id of user when login è is ok
var loginOK = false; var httpRequest; function validateLogin() { var login = document.getElementById("NomeForm"); var logintxt = login.value; var password = document.getElementById("PasswdForm"); var passwordtxt = password.value; var url = "/forum/checklogin.php?username=" + logintxt + "&password=" + passwordtxt; if (window.XMLHttpRequest) { // Mozilla, Safari, ... httpRequest = new XMLHttpRequest(); if (httpRequest.overrideMimeType) { httpRequest.overrideMimeType('text/xml'); } } else if (window.ActiveXObject) { // IE try { httpRequest = new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { httpRequest = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) {} } } if (!httpRequest) { alert('Giving up :( Cannot create an XMLHTTP instance'); return false; } httpRequest.onreadystatechange = loadLogin; httpRequest.open('GET', url, true); httpRequest.send(null); } function loadLogin() { if (httpRequest.readyState == 4) { if (httpRequest.status == 200) { response = httpRequest.responseText; if (response == "") { alert ('login/password errate.'); } else { var responseXML = httpRequest.responseXML.documentElement; user_id = responseXML.firstChild.nodeValue; LinkSitoForm = document.getElementById('LinkSitoForm'); LinkSitoForm.setAttribute('value', 'http://forum.cellularmagazine.it/profile.php?mode=viewprofile&u=' + user_id); NomeForm = document.getElementById('NomeForm'); PasswdForm = document.getElementById('PasswdForm'); PasswdForm.setAttribute('enabled','no'); var whchis = document.getElementById("trcheckpasswd"); whchis.innerHTML = "OK" } } else { alert('There was a problem with the request.'); } } else { } }