function checkName() {
	var parameter = document.getElementById('username').value;
	var url = "username_process.php?username=" + parameter;
	var callback = checkCompleted;

	document.getElementById('ajaxLoading').style.visibility = "visible";
	document.getElementById('ajaxLoading').style.display = "block";
	
	document.getElementById('output').style.visibility = "hidden";
	document.getElementById('output').style.display = "none";
	g_ajax_obj.CallXMLHTTPObjectGETParam(url, callback, parameter);
}

function checkCompleted(responseText, username) {
	var response = "";
	var available = "The username \"" + "<b><font color=\"##008080\">" + username + "</font></b>" + "\" is available! <br /> <a href=\"http://www.twitter.com/signup\">Sign Up Now</a>";
	var invalid = "The username \"" + "<b><font color=\"#8B008B\">" + username + "</font></b>" + "\" contains invalid characters!";
	var twitter = "The username \"" + "<b><font color=\"#1E90FF\">" + username + "</font></b>" + "\" contains twitter in the username, which is forbidden!";
	var unavailable = "The username \"" + "<b><font color=\"#DC143C\">" + username + "</font></b>" + "\" is already in use! <br /> <a href=\"http://www.twitter.com/" + username + "\">Visit the Profile</a>";
	var suspended = "The username \"" + "<b><font color=\"#FF8C00\">" + username + "</font></b>" + "\" has been suspended!";

	var empty = "Please enter a username!";
	var error = "An unknown error occurred!";

	document.getElementById('ajaxLoading').style.visibility = "hidden";
	document.getElementById('ajaxLoading').style.display = "none";
		
	document.getElementById('output').style.visibility = "visible";
	document.getElementById('output').style.display = "block";

	switch (responseText) {
		case "available":
			response = available;
			break;
		case "invalid":
			response = invalid;
			break;
		case "twitter":
			response = twitter;
			break;
		case "unavailable":
			response = unavailable;
			break;
		case "empty":
			response = empty;
			break;
		case "suspended":
			response = suspended;
			break;
		default:
			response = error;
			break;
	}
	document.getElementById('output').innerHTML = response;
}