var XmlHttpObj;

// create an instance of XMLHTTPRequest Object, varies with browser type, try for IE first then Mozilla
function CreateXmlHttpObj() {
	
	// try creating for IE (note: we don't know the user's browser type here, just attempting IE first.)
	try {
		XmlHttpObj = new ActiveXObject("Msxml2.XMLHTTP");
	} catch(e) {
		try {
			XmlHttpObj = new ActiveXObject("Microsoft.XMLHTTP");
		} catch(oc) {
			XmlHttpObj = null;
		}
	}
	
	// if unable to create using IE specific code then try creating for Mozilla (FireFox) 
	if(!XmlHttpObj && typeof XMLHttpRequest != "undefined") {
		XmlHttpObj = new XMLHttpRequest();
	}
}

function logMeIn(form) {
	
    var userName = document.getElementById("userName").value;
    
    // url of page that will send xml data back to client browser
	
	var requestUrl = "http://www.smoothfmlive.com/shoutBoxLogin.php";
	var params = "userName=" + encodeURIComponent(userName) ;
	    
	CreateXmlHttpObj();
	
	// verify XmlHttpObj variable was successfully initialized
	if(XmlHttpObj) {
        // assign the StateChangeHandler function ( defined below in this file)
        // to be called when the state of the XmlHttpObj changes
        // receiving data back from the server is one such change
		XmlHttpObj.onreadystatechange = StateChangeHandler;
		
		// define the iteraction with the server -- true for as asynchronous.
		XmlHttpObj.open("POST", requestUrl,  true);
		//Send the proper header information along with the request
		XmlHttpObj.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		XmlHttpObj.setRequestHeader("Content-length", params.length);
		XmlHttpObj.setRequestHeader("Connection", "close");
		
		// send request to server, null arg  when using "GET"
		XmlHttpObj.send(params);
		document.getElementById("shoutForm").innerHTML = '<img src="images/ajax-loader.gif" align="absmiddle">&nbsp;<span class="loading">Logging In...</span>'
	}
}

function StateChangeHandler() {
	// state ==4 indicates receiving response data from server is completed
	if(XmlHttpObj.readyState == 4) {
		// To make sure valid response is received from the server, 200 means response received is OK
		if(XmlHttpObj.status == 200) {
			document.getElementById('shoutForm').innerHTML = XmlHttpObj.responseText;
		} else {
			alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}