Converting word doc file to pdf with using Microsoft.Office.Interop.Word Dll

1.open the visual studio 2010 and add the references
using Microsoft.Office.Interop.Word;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml;
2.drag and drop one fileupload control,button and label
3.write the following code in the code behind

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.Office.Interop.Word;
using System.IO;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml;
using System.Text;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }
    public void ConvertTopdf(string path,string filename)
    {
    Microsoft.Office.Interop.Word.ApplicationClass wordApplication = null;
        Microsoft.Office.Interop.Word.Document wordDocument = null;

        // Declare a variable for the path of the file to convert. 
        string paramSourceDocPath = path;

        // Declare variables for the Document.ExportAsFixedFormat method parameters.
        string paramExportFilePath = @"I:\karthik\WebSite8\pdf\"+filename;
        Microsoft.Office.Interop.Word.WdExportFormat paramExportFormat = Microsoft.Office.Interop.Word.WdExportFormat.wdExportFormatPDF;
        //wdExportFormatXPS
        bool paramOpenAfterExport = false;
        Microsoft.Office.Interop.Word.WdExportOptimizeFor paramExportOptimizeFor = Microsoft.Office.Interop.Word.WdExportOptimizeFor.wdExportOptimizeForPrint;
        Microsoft.Office.Interop.Word.WdExportRange paramExportRange = Microsoft.Office.Interop.Word.WdExportRange.wdExportAllDocument;
        Int32 paramStartPage = 0;
        Int32 paramEndPage = 0;
        Microsoft.Office.Interop.Word.WdExportItem paramExportItem = Microsoft.Office.Interop.Word.WdExportItem.wdExportDocumentWithMarkup;
        bool paramIncludeDocProps = true;
        bool paramKeepIRM = true;
        Microsoft.Office.Interop.Word.WdExportCreateBookmarks paramCreateBookmarks = Microsoft.Office.Interop.Word.WdExportCreateBookmarks.wdExportCreateWordBookmarks;
        bool paramDocStructureTags = true;
        bool paramBitmapMissingFonts = true;
        bool paramUseISO19005_1 = false;
        try
        {
            // Start an instance of Word.
            wordApplication = new Microsoft.Office.Interop.Word.ApplicationClass();

            // Open the source document.
            wordDocument = wordApplication.Documents.Open(paramSourceDocPath);

            // Export it in the specified format.if (wordDocument != null)
            {
                wordDocument.ExportAsFixedFormat(paramExportFilePath, paramExportFormat, paramOpenAfterExport, paramExportOptimizeFor, paramExportRange, paramStartPage, paramEndPage, paramExportItem, paramIncludeDocProps, paramKeepIRM,
                paramCreateBookmarks, paramDocStructureTags, paramBitmapMissingFonts, paramUseISO19005_1);
            }
        }
        catch (Exception ex)
        {
            Label1.Text = ex.Message;
        }
        finally
        {
            // Close and release the Document object.if (wordDocument != null)
            {
               // wordDocument.Close(false);
                wordDocument = null;
            }
            // Quit Word and release the ApplicationClass object.if (wordApplication != null)
            {
                wordApplication.Quit(false);
                wordApplication = null;
            }
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
            GC.WaitForPendingFinalizers();
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            string extention = Path.GetExtension(FileUpload1.PostedFile.FileName);
            if (extention.ToLower() == ".doc" || extention.ToLower() == ".docx")
            {
                string path = Convert.ToString(System.IO.Path.GetFullPath(FileUpload1.PostedFile.FileName));
                string filename = TextBox1.Text;
                FileUpload1.SaveAs(@"I:\karthik\doc2pdf\TempDoc1\" + filename);
               
                ConvertTopdf(path,filename);
                Label1.Text = "File uplod Successfull";
            }
            else
            {
                Label1.Text = "please Select Word file";
            }
        }
        else
        {
            Label1.Text = "Please select The File";                
        }
    }
}