ASP.NET

if (FileUpload1.HasFile)
            {
                FileInfo branchinfo = new FileInfo(FileUpload1.PostedFile.FileName.Trim());
                byte[] branchcontent = new byte[branchinfo.Length];
                FileStream branchstream = branchinfo.OpenRead();
                branchstream.Read(branchcontent, 0, branchcontent.Length);
                branchstream.Close();
                cmdsave.Parameters.AddWithValue("@BranchPicture", (branchcontent == null? System.DBNull.Value: branchcontent));
            }
            else {

                cmdsave.Parameters.AddWithValue("@BranchPicture",DBNull.Value);
            
            }

<asp:UpdatePanel ID="pannelupdate" runat="server" ><ContentTemplate><asp:DropDownList ID="ddlconnectivity" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlconnectivity_SelectedIndexChanged"><asp:ListItem Value="DSL">DSL</asp:ListItem><asp:ListItem Value="Connect">Connect</asp:ListItem><asp:ListItem Value="Not Available">Not Available</asp:ListItem><asp:ListItem Value="Others">Others</asp:ListItem></asp:DropDownList></ContentTemplate><Triggers> 
<asp:AsyncPostBackTrigger ControlID="ddlconnectivity" EventName="SelectedIndexChanged" />
</Triggers></asp:UpdatePanel>


 protected void ddlconnectivity_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (ddlconnectivity.SelectedValue == "Dsl" || ddlconnectivity.SelectedValue == "Connect" || ddlconnectivity.SelectedValue == "Others")
        {

            txtconnectaccount.Visible=true;

        }
        else {
            txtconnectaccount.Visible = false;
        }
    }