How to move previous and next image from current selection in picturebox in C# windows application?

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;
using System.Collections;
using System.Net;
using System.Web;
using MSaddin;


namespace MSaddin
{
public partial class formDisplay : Form
{
int locX = 15;
int locY = 20;
int sizeWidth = 140;
int sizeHeight = 135;


public formDisplay()
{
InitializeComponent();
DynamciLabel();

}

private void butView_Click(object sender, EventArgs e)
{

DirectoryInfo Folder;
FileInfo[] Images;
Folder = new DirectoryInfo(@"C:\Users\Public\Pictures\Sample Pictures");
Images = Folder.GetFiles();
panelDisplay.Controls.Clear();

int locnewX = locX;
int locnewY = locY;
foreach (FileInfo img in Images)
{

if (img.Extension.ToLower() == ".png" || img.Extension.ToLower() == ".jpg" || img.Extension.ToLower() == ".gif" || img.Extension.ToLower() == ".jpeg" || img.Extension.ToLower() == ".bmp" || img.Extension.ToLower() == ".tif")
{

if (locnewX >= panelDisplay.Width - sizeWidth - 10)
{
locnewX = locX;
locY = locY + sizeHeight + 30;
locnewY = locY;
}
else
{

locnewY = locY;
}

loadImagestoPanel(img.Name, img.FullName, locnewX, locnewY);
locnewY = locY + sizeHeight + 10;
locnewX = locnewX + sizeWidth + 30;
}

}
imagescount(Images.Length - 1);

}

private void butImage_Click(object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(panelDisplay.Width, panelDisplay.Height);
panelDisplay.DrawToBitmap(bmp, new Rectangle(0, 0, panelDisplay.Width, panelDisplay.Height));
SaveFileDialog dlg = new SaveFileDialog();
// dlg.Filter = "JPG Files (*.JPG)|*.JPG";
dlg.FileName = "*";
dlg.DefaultExt = "bmp";
dlg.ValidateNames = true;
dlg.Filter = "Bitmap Image (.bmp)|*.bmp|Gif Image (.gif)|*.gif |JPEG Image (.jpeg)|*.jpeg |Png Image (.png)|*.png";
if (dlg.ShowDialog() == DialogResult.OK)
{
pictureDisplay.Image.Save(dlg.FileName);
}
}



private void DynamciLabel()
{
Label lab = new Label();
lab.Text = "Photogallery";
lab.Size = new Size(370, 50);
lab.Location = new Point(495, 16);
lab.Font = new Font("Times New Roman", 25);
lab.ForeColor = Color.White;
lab.AutoSize = false;
lab.TextAlign = ContentAlignment.MiddleLeft;
Color clr = Color.FromArgb(3, 186, 217);
lab.BackColor = clr;
Controls.Add(lab);

}



private void loadImagestoPanel(String imageName, String ImageFullName, int newLocX, int newLocY)
{
PictureBox ctrl = new PictureBox();
ctrl.Image = Image.FromFile(ImageFullName);
ctrl.BackColor = Color.White;
ctrl.Location = new Point(newLocX, newLocY);
ctrl.Size = new System.Drawing.Size(sizeWidth+20, sizeHeight+20);
ctrl.Padding = new System.Windows.Forms.Padding(10,20,10,20);
ctrl.BorderStyle = BorderStyle.None;
ctrl.SizeMode = PictureBoxSizeMode.StretchImage;
ctrl.