if (isset($_POST['btn-login']))
{
    $LoginID = mysqli_real_escape_string($conn, $_POST['username']);
    $Password = $_POST['password'];

    $sql = "SELECT *, SUBSTRING_INDEX(Name, ' ', 1) AS ShortName FROM users_db WHERE UserID = '".$LoginID."'";
    $res = mysqli_query($conn, $sql);
    $row = mysqli_fetch_array($res);

    $count = mysqli_num_rows($res); // if username/pass correct it returns must be 1 row
        if($count < 1 )
    {
        echo "errmsg1";
    }
    else if($count == 1 && $row['Password']==password_verify($Password, $row['Password']) && $row['AccountStatus']=="Pending")
    {
echo "errmsg2";
    else if($count == 1 && $row['Password']==password_verify($Password, $row['Password']) && $row['AccountStatus']=="Active")
//session variables set here.
}
else
{
echo "errmsg3";
}
}

<script>
/*
Login Validation Script
*/

$('document').ready(function()
{
     /* validation */
     $("#login-form").validate({
      rules:
      {
            password: {
            required: true,
            },
            username: {
            required: true,
            },
       },
       messages:
       {
            password:{
                      required: "Password field cannot be empty."
                     },
            username:{
                      required: "A Login ID is required."
                      },
       },
       submitHandler: submitForm
       });
       /* validation */

       /* login submit */
       function submitForm()
       {
            var data = $("#login-form").serialize();

            $.ajax({

            type : 'POST',
            url  : 'processlogin.php',
            data : data,
            beforeSend: function()
            {
                $("#loginerror").fadeOut();
                $("#btn-submit").html('<img src="include/btn-ajax-loader.gif" /> &nbsp; Verifying');
            },
            success :  function(response)
               {
                    if(response=="success"){
                        $("#btn-submit").html('<img src="include/btn-ajax-loader.gif" /> &nbsp; Signing In...');
                        setTimeout(' window.location.href = "index.php"; ',4000);
                    }
                    else if(response=="errmsg1"){
                        $("#loginerror").fadeIn(1000, function(){
                        $("#loginerror").html('<span>The Login ID provided does not exist.</span>');
                        $("#btn-submit").html('Login');
                        });
                    }
                    else if(response=="errmsg2"){
                        $("#loginerror").fadeIn(1000, function(){
                        $("#loginerror").html('<span>This account is Pending Activation.</span>');
                        $("#btn-submit").html('Login');
                        });
                    }
                    else if (response=="errmsg3"){
                        $("#loginerror").fadeIn(1000, function(){
                        $("#loginerror").html('<span">Unknown Error</span>');
                        $("#btn-submit").html('Login');
                                    });
                    }
              }
            });
                return false;
        }
       /* login submit */
});
</script>

catch(PDOException $e){
        echo $e->getMessage();