Login dengan jQuery, PHP + MySQL

<form action="" method="post" id="runLogin">
	<div class="form-group has-feedback">
		<input type="text" class="form-control username" name="username" placeholder="Username">
		<span class="glyphicon glyphicon-user form-control-feedback"></span>
	</div>
	<div class="form-group has-feedback">
		<input type="password" class="form-control password" name="password" placeholder="Password">
		<span class="glyphicon glyphicon-lock form-control-feedback"></span>
	</div>
	<div class="row">
		<div class="col-xs-6 pull-right">
			<input type="submit" class="btn btn-primary btn-block btn-flat" id="login" value="Sign In">
		</div>
	</div>
</form>

$(function() {
		
   $(".username").focus();

   $("#runLogin").submit(function(e) {
		e.preventDefault();
		
		$.ajax({
			url: "apps/Views/login/submit.php",
			type: "POST",
			dataType : 'json',
			data: $("#runLogin").serialize(),
			cache: false,
			beforeSend: function(){ $("#login").val('Connecting...');},
			success: function(html){
				if($.trim(html.msg) == 'OK'){
					window.location.href = "home";
				}
				else{
					$("#login").val('Sign In');
					$(".username").focus();
					$("#loadAlert").html('<div class="alert alert-warning alert-dismissible"><button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>'+$.trim(html.msg)+'</div>');
				}
			},
			error:function(xhr, status, error){
				$("#loadAlert").html('<div class="alert alert-danger alert-dismissible"><button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>'+error+'</div>');
			}
		});
		return false;
	});
});

url: "apps/Views/login/submit.php",
type: "POST",
dataType : 'json',

$data	= array(
	'username'	=> $_POST['username'],
	'password'	=> $_POST['password']
);

if(is_ajax())
{
	checkUser($data);
}

## FUNCTION
function checkUser($getData) 
{
	global $db_mysql;
	
	$arr 	= array();
	
	if($getData['username'] == "")
	{
		$arr['msg'] = 'Username masih kosong!';
	}
	else if($getData['password'] == "")
	{
		$arr['msg'] = 'Password masih kosong!';
	}
	else{
		$data = $db_mysql->select("SELECT * FROM tbl_users WHERE username = '$getData[username]' AND password = md5('$getData[password]') AND active = '1'");
		
		if(count($data) > 0)
		{
			$_SESSION['SESS_ID'] 	    = $data[0]['user_id'];
            $_SESSION['SESS_LOGIN_ID'] 	= $data[0]['username'];
			$_SESSION['SESS_NAME']		= $data[0]['first_name'].' '.$data[0]['last_name'];
			$_SESSION['SESS_GROUP'] 	= $data[0]['group_id'];
			$_SESSION['SESS_ACTIVE'] 	= $data[0]['active'];
			
			$arr['msg'] = 'OK';
		}
		else{
			$arr['msg'] = 'Login gagal, coba lagi!!';
		}
	}
	echo json_encode($arr);
}

--
-- Table structure for table `tbl_users`
--
DROP TABLE IF EXISTS `tbl_users`;
CREATE TABLE `tbl_users` (
  `user_id` int(11) NOT NULL,
  `username` varchar(50) DEFAULT NULL,
  `password` varchar(32) DEFAULT NULL,
  `group_id` tinyint(4) DEFAULT NULL,
  `first_name` varchar(50) DEFAULT NULL,
  `last_name` varchar(50) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `active` tinyint(4) DEFAULT NULL,
  `usr_img` text,
  `updateBy` int(11) NOT NULL,
  `create_date` datetime DEFAULT NULL,
  `modified_date` datetime DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
--
-- Indexes for table `tbl_users`
--
ALTER TABLE `tbl_users`
  ADD PRIMARY KEY (`user_id`);
--
-- AUTO_INCREMENT for table `tbl_users`
--
ALTER TABLE `tbl_users`
  MODIFY `user_id` int(11) NOT NULL AUTO_INCREMENT;