Set page margin and orientation in word document using C# in ASP.Net

Hi PRA,

Refer below sample.

protected void Search(object sender, EventArgs e)
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[5] { 
    new DataColumn("LastName"), new DataColumn("Name"),new DataColumn("FatherName"), 
    new DataColumn("Birthday"),new DataColumn("Adress") });
    dt.Rows.Add("Pulodov", "Rustam", "Abdulloevich", "22.12.1987", "city Dushanbe");
    dt.Rows.Add("Soliev", "Firuzjon", "Mirzonovich", "16.06.1988", "city Hisor");
    dt.Rows.Add("Malaev", "Nurullo", "Karimovich", "25.03.1986", "city Dushanbe");

    if (!string.IsNullOrEmpty(txtSearch.Text.Trim()))
    {
        if (dt.Rows.Count > 0)
        {
            DataTable dtFinal = dt.Select("LastName = '" + txtSearch.Text.Trim() + "'").CopyToDataTable();

            object fileName = Server.MapPath("~/Files/Test.doc");
            Word.Application word = new Word.Application();
            Word.Document doc = new Word.Document();
            object missing = System.Type.Missing;
            try
            {
                doc = word.Documents.Open(ref fileName, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing,
                    ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing);
                doc.PageSetup.Orientation = Word.WdOrientation.wdOrientLandscape; // Set page orientation
                doc.PageSetup.LeftMargin = 0.5f; // Set page left margin
                doc.Activate();
                bool lastNameChanged = false, nameChanged = false, fatherNameChanged = false, birthdayChanged = false, adressChanged = false;
                foreach (Microsoft.Office.Interop.Word.Range docRange in doc.Words)
                {
                    if (docRange.Text.Trim() == "LastName")
                    {
                        if (!lastNameChanged)
                        {
                            docRange.Text = docRange.Text.Replace("LastName", "LastName: " + dtFinal.Rows[0]["LastName"].ToString());
                            lastNameChanged = true;
                        }
                    }
                    else if (docRange.Text.Trim() == "Name")
                    {
                        if (!nameChanged)
                        {
                            docRange.Text = docRange.Text.Replace("Name", "Name: " + dtFinal.Rows[0]["Name"].ToString());
                            nameChanged = true;
                        }
                    }
                    else if (docRange.Text.Trim() == "FatherName")
                    {
                        if (!fatherNameChanged)
                        {
                            docRange.Text = docRange.Text.Replace("FatherName", "FatherName: " + dtFinal.Rows[0]["FatherName"].ToString());
                            fatherNameChanged = true;
                        }
                    }
                    else if (docRange.Text.Trim() == "Birthday")
                    {
                        if (!birthdayChanged)
                        {
                            docRange.Text = docRange.Text.Replace("Birthday", "Birthday: " + dtFinal.Rows[0]["Birthday"].ToString());
                            birthdayChanged = true;
                        }
                    }
                    else if (docRange.Text.Trim() == "Adress")
                    {
                        if (!adressChanged)
                        {
                            docRange.Text = docRange.Text.Replace("Adress", "Adress: " + dtFinal.Rows[0]["Adress"].ToString());
                            adressChanged = true;
                        }
                    }
                }
                foreach (Microsoft.Office.Interop.Word.Range docRange in doc.Words)
                {
                    if (docRange.Text.Trim() == ":")
                    {
                        docRange.Text = docRange.Text.Replace(":", " ");
                    }
                }
                doc.Save();
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
            finally
            {
                doc.Close(ref missing, ref missing, ref missing);
                ((Word._Application)word).Quit();
            }
        }
    }
}