var xmlhttp;
function submitLogin(){
	var username = document.getElementById('Username').value;
	var password = document.getElementById('Password').value;
	var username_password = username + '_' + password;
	var errMsg = "";
	switch(username_password.indexOf('_'))
	{
		case 0:
			errMsg = (username_password.length > 1)? "\"Please enter your username.\"":"\"Please enter your username and password.\"";
			break;
		default:
			errMsg = (username_password.indexOf('_') == (username_password.length - 1))? "\"Please enter your password.\"":"";
			break;
	}
	(errMsg.length > 0)?showErrorMessage(errMsg,'errorMessages'):loginUser(username,password);
}

function showErrorMessage(msg, divId){
	document.getElementById(divId).innerHTML=msg;
}

function loginUser(username, password)
{
	xmlhttp=GetXmlHttpObject();
	if (xmlhttp==null)
	  {
	  alert ("Browser does not support HTTP Request");
	  return;
	  }
		var url="checkloginjx.php";
		var params = "Username="+username;
		params += "&Password="+password;
		xmlhttp.open("POST",url,true);
		
		//Send the proper header information along with the request
		xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		xmlhttp.setRequestHeader("Content-length", params.length);
		xmlhttp.setRequestHeader("Connection", "close");
		xmlhttp.onreadystatechange=stateChanged;
		
		xmlhttp.send(params);
}

function stateChanged()
{
	if (xmlhttp.readyState==4)
	{
		if(xmlhttp.responseText.indexOf('Succeed') != -1){
			showWelcomeMessage(document.getElementById('Username').value);
		}
		else{
			showErrorMessage(xmlhttp.responseText, 'errorMessages');
		}
			
	}
}

function registerResults()
{
	if (xmlhttp.readyState==4)
	{ 
		showErrorMessage(xmlhttp.responseText,"registerErrorMessages");
		if(xmlhttp.responseText.indexOf('success') != -1)
		{
			showWelcomeMessage(document.getElementById('Username').value);
		window.location="index.php";
		}
	}
}

function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  return new XMLHttpRequest();
  }
if (window.ActiveXObject)
  {
  // code for IE6, IE5
  return new ActiveXObject("Microsoft.XMLHTTP");
  }
return null;
}

function showWelcomeMessage(username){
	document.getElementById('loginSection').innerHTML = '<h3>&nbsp;&nbsp;Welcome ' + username + '&nbsp;<a href="logout.php" style="color:purple">(Logout)</a></h3> <br />';
}

function register_user(){
	xmlhttp=GetXmlHttpObject();
	if (xmlhttp==null)
	  {
	  alert ("Browser does not support HTTP Request");
	  return;
	  }
		var url="register_action.php";
		var params = getParamsFromForms();
		xmlhttp.open("POST",url,true);
		
		//Send the proper header information along with the request
		xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		xmlhttp.setRequestHeader("Content-length", params.length);
		xmlhttp.setRequestHeader("Connection", "close");
		xmlhttp.onreadystatechange=registerResults;
		xmlhttp.send(params);
	
}

function getParamsFromForms(){
	var params = "";
	for(var f = 0; f < document.forms.length;f++){
		for(var e=0; e < document.forms[f].elements.length; e++)
		{
			params += document.forms[f].elements[e].name + "=" + document.forms[f].elements[e].value + "&";
		}
	}
	return params;
}