namespace WebCertifyNow.Main
{
    public partial class ViewFile : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (Request.QueryString.Get("Id") != null) 
            {
                Response.Clear();

                Guid id = new Guid(Request.QueryString.Get("Id"));
                if (id != Guid.Empty)
                {
                    File myFile = FileStorageManager.GetFile(id);

                    Response.ContentType = myFile.ContentType;

                    if (myFile.ContainsFile)
                    {
                        Response.BinaryWrite(myFile.FileData);
                    }
                    else
                    {
                        Response.Redirect(System.IO.Path.Combine(FileStorageManager.UploadsFolder, myFile.FileUrl));
                    }
                }
                else
                    Response.Redirect("~/Main/SubmittedQuestionnaire.aspx");
            }
            else
            {
                Response.Redirect("~/Main/SubmittedQuestionnaire.aspx");
            }
        }
    }
}

 


<asp:GridView ID="GridView1" runat="server" DataSourceID="AnswerDataSource" AutoGenerateColumns="False"
            Width="687px" BackColor="#CCCCCC" BorderColor="#999999" BorderStyle="Solid" BorderWidth="3px"
            CellPadding="4" ForeColor="Black" RowHeaderColumn="CertificationName" CellSpacing="2"
            OnRowDataBound="GridView1_RowDataBound">
            <Columns>
                  
                <asp:BoundField DataField="QuestionText" HeaderText="QuestionText" SortExpression="QuestionText" />
                <asp:BoundField DataField="DetailText" HeaderText="DetailText" SortExpression="DetailText" />
                <asp:CheckBoxField DataField="YesNoBoolValue" HeaderText="YesNoBoolValue" SortExpression="YesNoBoolValue" />
                <asp:BoundField DataField="DocumentName" HeaderText="AttachedDocument" SortExpression="DocumentName" />
                <asp:HyperLinkField DataTextField="DocumentName" HeaderText="DocumentName" SortExpression="DocumentName"
                    DataNavigateUrlFields="AttachedDocumentId" DataNavigateUrlFormatString="ViewFile.aspx?Id={0}"
                    NavigateUrl="~/Main" />
            </Columns>
            <FooterStyle BackColor="#CCCCCC" />
            <HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="#CCCCCC" ForeColor="Black" HorizontalAlign="Left" />
            <RowStyle BackColor="White" />
            <SelectedRowStyle BackColor="#000099" Font-Bold="True" ForeColor="White" />
            <SortedAscendingCellStyle BackColor="#F1F1F1" />
            <SortedAscendingHeaderStyle BackColor="#808080" />
            <SortedDescendingCellStyle BackColor="#CAC9C9" />
            <SortedDescendingHeaderStyle BackColor="#383838" />
        </asp:GridView>