<form class="form-horizontal" id="loginform"   method="post">
                    <div class="form-group">
                        <label for="userid" class="col-sm-3 control-label">User ID</label>
                        <div class="col-sm-9 has-feedback">
                            <input type="text" class="form-control" id="userid" name="userid" placeholder="Enter Your User ID" required>
                            <span class="glyphicon glyphicon-user form-control-feedback"></span>
                        </div>
                    </div>
                    <div class="form-group">
                        <label for="password" class="col-sm-3 control-label">Password</label>
                        <div class="col-sm-9 has-feedback">
                            <input type="password" class="form-control" id="password" name="password" placeholder="Enter Your Password" required>
                            <span class="glyphicon glyphicon-lock form-control-feedback"></span>
                        </div>
                    </div>
                    <div class="form-group">
                        <div class="col-xs-4 col-xs-offset-8">
                            <button type="submit" id="submit" class="btn btn-danger btn-block btn-flat">Sign In</button>
                        </div>
                    </div>


                </form>

$query = mysqli_query($link,"SELECT * FROM user WHERE USER_USERNAME = '".$userid."' AND USER_PASSWORD = '".$password."'");
            $numrows = mysqli_num_rows($query);
            if ($numrows!==0)
            {
                while($row = mysqli_fetch_assoc($query))
                {
                    @$_SESSION['session_userid'] = $row['USER_USERNAME'];
                    @$_SESSION['session_accounttype'] = $row['ACCESS_ID'];
                }
                //Location Depends on the User Type
                if($_SESSION['session_accounttype']=="1")
                {
                        echo 'true';
                }
                }
          else
            {
                echo 'false';
            }
    ?>

$(document).ready(function(){
    $("#add_err").css('display', 'none', 'important');
     $("#submit").click(function(){
          username=$("#userid").val();
          password=$("#password").val();
          $.ajax({
           type: "POST",
           url: "../basefunction/login.php",
            data: "userid="+username+"&password="+password,
           success: function(html){
            if(html=='true')    {
             //$("#add_err").html("right username or password");
             window.location="admin";
            }
            else    {
            $("#add_err").css('display', 'inline', 'important');
             $("#add_err").html("<img src='images/alert.png' />Wrong username or password");
            }
           },
           beforeSend:function()
           {
            $("#add_err").css('display', 'inline', 'important');
            $("#add_err").html("<img src='images/ajax-loader.gif' /> Loading...")
           }
          });
        return false;
    });
});