p1fieldid = "fl_pass1";
p2fieldid = "fl_pass2";
emailfieldid = "fl_email";

userfieldid = "fl_username";
userchkspan = "fl_chkok";
passmatch = "fl_passmatch";
signupbutton = "signupbtn";

userok = false;

function chkuser(a){
  if (a == 0) {
    //document.getElementById(userchkspan).innerHTML = "";
  } else {
    var u = document.getElementById(userfieldid).value;
    if ((u.length >= 6) && (u.length <= 20)) {
      var opt = Object.toQueryString({'a':'s', 'u': u});
      document.getElementById(userchkspan).innerHTML = "กำลังตรวจสอบ";
      gflxhr = new XHR({method:'post', onSuccess : chkuser_cb}).send('http://www.exteen.com/checkstatus', opt);
    } else {
      document.getElementById(userchkspan).innerHTML = "ชื่อสั้น หรือยาวเกินไป";
      userok = false;
    }
  }
  chkbtn();
}

function chkbtn(){
  var pm = false;
  if (document.getElementById(p1fieldid).value != document.getElementById(p2fieldid).value) {
    document.getElementById(passmatch).innerHTML = " (พาสเวิร์ดไม่ตรงกัน)";
  } else {
    document.getElementById(passmatch).innerHTML = "";
    pm = true;
  }

  var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
  
  if (pm && (document.getElementById(p1fieldid).value.length > 5) && filter.test(document.getElementById(emailfieldid).value) && userok &&
      document.getElementById('fl_agreement').checked && (document.getElementById('fl_blogtitle').value != "") && (document.getElementById('fl_screenname').value != "")) {
    document.getElementById(signupbutton).disabled = false;
  } else {
    document.getElementById(signupbutton).disabled = true;
  }  
  
}

function chkuser_cb(resp){
  var data = Json.evaluate(resp);
  if (data[0] == 0) {
    document.getElementById(userchkspan).innerHTML = "ไม่สามารถใช้ชื่อนี้ได้";
    userok = false;
  } else if (data[0] == 1) {
    document.getElementById(userfieldid).value = data[1];
    document.getElementById(userchkspan).innerHTML = "OK";
    userok = true;
  }
  chkbtn();
}