var xmlHttp;

function createXMLHttpRequest() {
 if (window.ActiveXObject) {
     xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
 }
 else if (window.XMLHttpRequest) {
          xmlHttp = new XMLHttpRequest();
 }
}

function Login_Ajax() {
         createXMLHttpRequest();
         var url = "../js/login_ajax.php";
         var postStr = "action=login";
         xmlHttp.open("POST",url,true);
         xmlHttp.onreadystatechange=Handle_Login_Ajax;
         xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
         xmlHttp.send(postStr);
}

function Handle_Login_Ajax() {
         if (xmlHttp.readyState==4) {
   	         if (xmlHttp.status==200) {  
   	         	 if (xmlHttp.responseText != "") {
   	         	 	 var return_value = xmlHttp.responseText;
                     //alert(return_value);   	         	 	     
   	         	     document.getElementById('username').innerHTML = return_value;
   	         	 }
   	         }
         }
}
function Logout_Ajax() {
    createXMLHttpRequest();
    var url = "../js/login_ajax.php";
    var postStr = "action=logout";
    xmlHttp.open("POST",url,true);
    xmlHttp.onreadystatechange=Handle_Logout_Ajax;
    xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    xmlHttp.send(postStr);
}

function Handle_Logout_Ajax() {
    if (xmlHttp.readyState==4) {
	         if (xmlHttp.status==200) {  
	         	 if (xmlHttp.responseText != "") {
	         	 	 var return_value = xmlHttp.responseText;
                //alert(return_value);   	         	 	     
	         	     document.getElementById('username').innerHTML = return_value;
	         	 }
	         }
    }
}