How I can save name of uploaded file in database

hi

I have 1 fileupload control that I can upload file from it below is code :

int count = 0;
        if (this.fuppdf.HasFile && !string.IsNullOrEmpty(this.txtarticle.Text))
        {
 string[] validext = { ".pdf" };
        //string ext = System.IO.Path.GetExtension(fuppdf.PostedFile.FileName);
        string ext = Path.GetExtension(fuppdf.PostedFile.FileName);
        string[] files = Directory.GetFiles(Server.MapPath("~/image/House/article/pdf/"));
        if (Array.IndexOf(validext, ext.ToLower()) < 0)
        {
            lblpdf.Text = "* upload pdf files.";
            return;
        }
        if (File.Exists(Server.MapPath("~/image/House/article/pdf/") + this.txtarticle.Text + ext))
        {
            foreach (string s in files)
            {
                string filename = string.Empty;
                filename = Path.GetFileName(s).Substring(0, Path.GetFileName(s).LastIndexOf("."));
                if (filename.Contains("("))
                {
                    filename = filename.Substring(0, filename.LastIndexOf("("));
                }
                if (filename == this.txtarticle.Text.Trim())
                {
                    count++;
                }
            }          this.fuppdf.PostedFile.SaveAs(Server.MapPath("~/image/House/article/pdf/") + this.txtarticle.Text + "(" + count.ToString() + ")" + ext);

        }
        else
        {
            this.fuppdf.PostedFile.SaveAs(Server.MapPath("~/image/House/article/pdf/") + this.txtarticle.Text + ext);
        }

and with below code I want save filename (uploaded filename) in database

   SqlCommand _cmd = new SqlCommand("Fileuppdf", _cn);
        _cmd.CommandType = CommandType.StoredProcedure;
        string data = Session["behcode"].ToString();
        _cn.Open();
        _cmd.Parameters.AddWithValue("@pdf", filename);
       _cmd.Parameters.AddWithValue("@Behcode", data);
        _cmd.Parameters.AddWithValue("@id", Convert.ToInt32(ViewState["Id"]));

but it make error in this line

_cmd.Parameters.AddWithValue("@pdf", filename);

error===>("The name 'filename' doesn't exist in the current context")

I know that I define filename in 

foreach (string s in files) but I don't know how I can save it name in database

Best Regards

Neda