var request;

function getXMLHttpRequest() {
	var request = null;
	if (window.XMLHttpRequest()) {
		request = new XMLHttpRequest();
	} else if (typeof ActiveXObject != 'undefined') {
		request = new ActiveXObject("Microsoft.XMLHTTP");
	}
	return request;
}

function postRequest(url, params) {

  // global variable @request
	request = getXMLHttpRequest();

	if (request) {
		request.open("POST", url, true);
		request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		request.onreadystatechange = stateChange;
		request.send(params);
	}
}

function stateChange() {
  var state = request.readyState;
  var data;
  
  if (state == 4) {
    data = request.responseText;
  } else {
    data = "Sending Comment ...";
  }
  
  document.getElementById("ajaxform").innerHTML = data;
}

function submitForm() {
  var url = "Scripts/contactus-main.php";
  var params = "";

  params += "name=" + document.getElementById("name").value;
  params += "&email=" + document.getElementById("email").value;
  params += "&phone=" + document.getElementById("phone").value;
  params += "&comment=" + document.getElementById("comment").value;

  postRequest(url, params);
}