Excel File Upload Error - Access to the path ..url Here..is denied.

String filepath = Server.MapPath("UploadData");
        FileUpload1.SaveAs(filepath + "\\" + FileUpload1.FileName.Split('\\')[FileUpload1.FileName.Split('\\').Length - 1]);
        string excelPath = (filepath + "\\" + FileUpload1.FileName.Split('\\')[FileUpload1.FileName.Split('\\').Length - 1]);
        string OledbConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excelPath + ";Extended Properties=Excel 8.0;";
        OleDbConnection cn = new OleDbConnection(OledbConnectionString);
        cn.Open();
        try
        {
            string query = string.Format(" select * from [{0}]", "Sheet1$");
            OleDbDataAdapter ad = new OleDbDataAdapter(query, cn);
            DataSet ds = new DataSet();
            ad.Fill(ds, "Attendance");
         
            DataTable dt = ds.Tables[0];
            foreach (DataRow dr in dt.Rows)
            {
                string FName = dr[0].ToString();
                string Lname = dr[1].ToString();
                string Att = dr[2].ToString();
                string QU = "insert into ABC values('" + FName + "','" + Lname + "','" + Att + "')";
                SqlConnection cnp = new SqlConnection(bl.Cn);
                cnp.Open();
                SqlCommand cmd = new SqlCommand(QU,cnp);
                cmd.ExecuteNonQuery();
                cn.Close();
                cnp.Close();
                
                
            }
            Label1.Text = "ok";
        }
        catch (Exception e)
        {
            cn.Close();
            Label1.Text = e.Message;
        }
    }