Play flash and picture ads by checking the extention

See more:

C#

i have windows application which plays flash and images in certain intervals at the same location
here in the below code i am using the particular directory and particular file(like Top_1.swf and for image D:\.....)but i want like
i have to play flash or picture by finding their extension not by default giving their name.

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;

namespace Demo_Flash
{
    public partial class Form1 : Form
    {
        Timer timer1 = new Timer();
        Timer timer2 = new Timer();
        Timer timer3 = new Timer();

        int i = 0;
        int j = 0;
        public Form1()
        {
            InitializeComponent();
            i = 1;
            j = 1;
            timer1.Tick += new EventHandler(timer1_Tick);
            timer1.Interval = (1000) * 10;
            timer1.Enabled = true;
            timer1.Start();

            timer2.Tick += new EventHandler(timer2_Tick);
            timer2.Interval = (1000) * 10;
            timer2.Enabled = false;
            
            timer3.Tick += new EventHandler(timer3_Tick);
            timer3.Interval = (1000) * 5;
            timer3.Enabled = true;
            timer3.Start();            
        }

        void timer1_Tick(object sender, EventArgs e)
        {
            pictureBox1.Visible = false;
            pictureBox1.Enabled = false;
            axShockwaveFlash1.Visible = true;
            axShockwaveFlash1.BringToFront();
  
            if (i == 1)
            {
                string path = System.Environment.CurrentDirectory;
                path += @"\Top_1.swf";
                axShockwaveFlash1.LoadMovie(0, path);
                axShockwaveFlash1.Play();
                i++;
            }
            else if (i == 2)
            {  
                string path = System.Environment.CurrentDirectory;
                path += @"\Top_2.swf";
                axShockwaveFlash1.LoadMovie(0, path);
                axShockwaveFlash1.Play();
                i--;
            }
 
        }

        void timer2_Tick(object sender, EventArgs e)
        {
            axShockwaveFlash1.Visible = false;
            pictureBox1.BringToFront();
            pictureBox1.Visible = true;
            pictureBox1.Enabled = true;
            
            if (j == 1)
            {        
                pictureBox1.Image = Image.FromFile("D:/Project Source/Experimented/Bulk Sms/ProjectSms/ProjectSms/bin/Debug/Advertisement1_1.jpg");
                j++;
            }
            else if (j == 2)
            {
               pictureBox1.Image = Image.FromFile("D:/Project Source/Experimented/Bulk Sms/ProjectSms/ProjectSms/bin/Debug/Advertisement2_1.jpg");
                j--;
            }
        }

        void timer3_Tick(object sender, EventArgs e)
        {
            timer3.Enabled = false;
            timer2.Enabled = true;
            timer2.Start();
        }
    }
}

any one know the answer please help me

[edit]Formatted within tags - tags do nothing with unformatted input![/edit]