var xmlHttp
	function login(){	
		xmlHttp=GetXmlHttpObject()
		if(xmlHttp==null){
			alert("Browser does not support HTTP Request");
			return;
		}
		var qstr;
		var rmb = (document.getElementById('rememberMe').checked? "y":"n");
		var loginName = document.getElementById('loginName').value;
		var password = document.getElementById('password').value;
		if(valU(loginName,password)){
			qstr  = "loginName="+loginName
			qstr += "&password="+password
			qstr += "&rememberMe="+rmb;
			xmlHttp.onreadystatechange = loginResult;
			xmlHttp.open("POST","ajax/login_out.php",true);
			xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
			xmlHttp.send(qstr);
		}else{
			document.getElementById('loader').innerHTML = "Username and password required";
			return false;	
		}
	}
	//login result
	function loginResult(){ 
		if(xmlHttp.readyState == 3){
			document.getElementById('loader').innerHTML = '<img src="images/loaderWhiteBG.gif" width="190" height="23" />';
		}else if (xmlHttp.readyState == 4 || xmlHttp.readyState == "complete"){
			switch(xmlHttp.responseText){
				case "1": //Login approved
					window.location = "./main.php";
					break;
				case "0"://invalid login details
					document.getElementById('loader').innerHTML = "Invalid username or password";
					return false;	
					break;
				case "3":
					document.getElementById('loader').innerHTML = "Error logging in";
					return false;
					break;
			}
		}
	}
	/*** Log out function ***/
	function logout(){
		xmlHttp=GetXmlHttpObject()
		if(xmlHttp==null){
			alert("Browser does not support HTTP Request");
			return;
		}
		var qstr;	
		qstr  = "logout=logout";
		xmlHttp.onreadystatechange = logoutResult;
		xmlHttp.open("POST","ajax/login_out.php",true);
		xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		xmlHttp.send(qstr);
	}
	//logout result
	function logoutResult(){ 
		if(xmlHttp.readyState == 4 || xmlHttp.readyState == "complete"){ 
			switch(xmlHttp.responseText){
				case "1":
					window.location = "./index.php";
					break;
			}
		}
	}
	/*** Validation, Check user has entered details ***/
	function valU(nm,ps){
		theName = (nm==""?false:true);
		thePass = (ps==""?false:true);
		if(theName && thePass){
			return true;
		}else{
			return false;	
		}
	}
	function GetXmlHttpObject(){
		var xmlHttp=null;
		try{
			// Firefox, Opera 8.0+, Safari
			xmlHttp=new XMLHttpRequest();
		}catch (e){
			// Internet Explorer
			try{
				xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			}catch (e){
				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
		}
		return xmlHttp;
	}