how to take screenshot of Webpage -while URL picked from a uploaded file..

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 MSDN_wbc_tut1
{
    public partial class Form1 : Form
    {

        public int temp = 0;
        public Form1()
        {
            InitializeComponent();
        }



        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void FileUploadButton1_Click(object sender, EventArgs e)
        {
            
            //once a file is uploaded i want Pgm to read contents & browse them as URLS

            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.CheckFileExists = true;
            openFileDialog.AddExtension = true;
            openFileDialog.Multiselect = true;
            //Filtering for Text files alone
            openFileDialog.Filter = "text files (*.txt)|*.txt";

            //if file is selected we must then do our coding part to proceed hecneforth 

            if (openFileDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            { 
            //my code to say pgm wat to do once upload done...

                //Getting my Chosen file's name 
         string Fileuploaded = openFileDialog.FileName;

                //Read all line opens files - reads till EOF & closes ,prevents a while condition
                string[] FileuploadedContent = System.IO.File.ReadAllLines(Fileuploaded);

                foreach (string s in FileuploadedContent)
                {
                    NavigateContent(s);
                }
            }
        }

        private void NavigateContent(string lineasurl)
        {
             // Add an event handler that images the document after it loads.
   
            try 
            {
                webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(takescreen);
                webBrowser1.Navigate(new Uri(lineasurl));
                //webBrowser1.Navigate(lineasurl); also works
                                
            }

            catch (System.UriFormatException)
            {
                return;
            }
        
        }


        private void takescreen(object sender,WebBrowserDocumentCompletedEventArgs e)
            {

            int x = 600, y = 700;
            Bitmap bitmap = new Bitmap(x, y);
            webBrowser1.DrawToBitmap(bitmap, new Rectangle(0, 0, x, y));
            temp = temp + 1;

            string TempFname = "Screenshotref"+temp.ToString()+ "." + "jpg";
            bitmap.Save(TempFname);
        
        
        }

        private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {

        }
       
    }

  
}