如何保持用户登录，如果“记住我”;复选框被选中

我想保持用户登录，即使他/她刷新或关闭浏览器。

这是我的代码:

index . php

<?php 
include_once('elogFiles/view/myIncludes.php');
?>

        <div class="container"  id="myLogin">
            <div class="row">
                    <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-hidden="true">
                        <div class="modal-dialog">
                            <div class="modal-content">
                                <div class="modal-header">
                                    <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
                                    <h5 class="modal-title">PLEASE ENTER YOUR EMAIL ADDRESS AND PASSWORD TO LOG IN.</h5>
                                </div>
                                <div class="modal-body">
                                <div id="show" class="lalert lalert-warning"></div> 
                                    <div class="form-horizontal">
                                        <div class="form-group">
                                            <label for="email" class="col-sm-2 control-label">Email</label>
                                            <div class="col-md-9">
                                                <div class="input-group">
                                                    <span class="input-group-addon"><i class="fa fa-envelope-o fa-fw"></i></span>
                                                    <input type="text" name="lemail" id="lemail" value="<?php echo $unm ?>" class="form-control" placeholder="Enter Email Address..." />
                                                </div>
                                            </div>
                                        </div>
                                        <div class="form-group">
                                            <label for="password" class="col-sm-2 control-label">Password</label>
                                            <div class="col-md-9">
                                                <div class="input-group">
                                                    <span class="input-group-addon"><i class="fa fa-key fa-fw"></i></span>
                                                    <input type="password" name="lpassword" id="lpassword" value="<?php echo $pwd ?>" class="form-control" placeholder="Enter Password..." />
                                                </div>
                                            </div>
                                        </div>
                                        <div class="form-group">
                                            <div class="col-sm-offset-2 col-sm-10">
                                                <input type="checkbox" name="chkbox" value="staylogged" class="checkbox-inline" />
                                                <label>  &nbsp; Keep me logged in</label>  &nbsp; <b>|</b>
                                                <a href="" style="text-decoration:none">  &nbsp; Forgot your password?</a>
                                            </div>
                                        </div>
                                        <div class="form-group">
                                            <div class="col-sm-offset-2 col-sm-10">
                                                <button type="submit" id="login" name="login" class="btn btn-primary"><span class="glyphicon glyphicon-user"></span> Login</button>
                                                <button type="button" class="btn btn-info show-page modal-btn" data-page="Signup"  data-dismiss="modal" aria-hidden="true"><span class="glyphicon glyphicon-list-alt"></span> Register</button>
                                            </div>
                                        </div>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
            </div>
        </div>

myIncludes.php

<?php 
session_start();
$unm=isset($_SESSION['lemail'])?$_SESSION['lemail']:'';
$pwd=isset($_SESSION['lpassword'])?$_SESSION['lpassword']:'';
?>

savestate.php

<?php
session_start();
$_SESSION['lemail']=$_POST['lemail'];
$_SESSION['lpassword']=$_POST['lpassword'];
?>

脚本:

$(document).ready(function(){ 
     $('[name="chkbox"]').on('click', function(){
         $.post( "elogFiles/view/savestate.php", { email: $('[name="lemail"]').val(), password: $('[name="lpassword"]').val() }).done(function( data ) {
          });
     });
});