I have following code for excel reading

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C#

OleDbConnection conn = new OleDbConnection();
    OleDbCommand cmd = new OleDbCommand();
 
    OleDbDataAdapter da = new OleDbDataAdapter();
    DataSet ds = new DataSet();
    System.Data.DataTable dt = null;
    //string query = null;
    string connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0;HDR=YES;""";
   
    protected void Page_Load(object sender, EventArgs e)
    {
        //ConfigurationSettings.AppSettings[FileExtension];
        
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string validFileExtensions = Config.Get("ValidFileExtension");


        int uploadSize = Convert.ToInt32( Config.Get("DocUploadValidationSize"));
        string validationMEssage = Config.Get("DocUploadValidationMessage");

        connectionString = string.Format(connectionString, @"d:\R and D\Book1.xlsx");
          if (FileUpload1.HasFile)
          {
            string fileExt =
               System.IO.Path.GetExtension(FileUpload1.FileName);

            if (validFileExtensions.IndexOf(fileExt)>=0)
            {
                try
                {

                  if (FileUpload1.PostedFile.ContentLength >= uploadSize)
                    {

                        Literal1.Text = validationMEssage;
                        return;
                    }
        
                        FileUpload1.SaveAs(@"C:\Users\user5\Desktop" +
                        FileUpload1.FileName);
                        Label1.Text = "File name: " +
                        FileUpload1.PostedFile.FileName + "<br>" +
                        FileUpload1.PostedFile.ContentLength + " kb<br>" +
                        "Content type: " +
                        FileUpload1.PostedFile.ContentType;


                        using (OleDbConnection conn = new OleDbConnection(connectionString))
                        { 
                            conn.Open();

                            OleDbCommand cmd = conn.CreateCommand();
                            dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

                             
                            

                            String[] excelSheets = new String[dt.Rows.Count];
                            int i = 0;

                            // Add the sheet name to the string array.

                            foreach (DataRow row in dt.Rows)
                            {
                                  excelSheets[i] = row["TABLE_NAME"].ToString();
                                i++;
                            }

                            // Loop through all of the sheets if you want too...

                            for (int j = 1; j < excelSheets.Length; j++)
                            {

                                if (j == 1)
                                {
                                    cmd.CommandText = "SELECT ID,UserName,Designation FROM [" + excelSheets[1] + "]";
                                }
                                
                                else
                                    if (j == 2)
                                    {
                                        cmd.CommandText = "SELECT ID,CITY,STATE FROM [" + excelSheets[2] + "]";
                                    }


                                else
                                        if (j == 3)
                                        {
                                            cmd.CommandText = "SELECT ID,Client,City FROM [" + excelSheets[3] + "]";
                                        }
                                 
                                //cmd.CommandText = "SELECT ID,City,State FROM [WorkSheet2$]";
                                //cmd.CommandText = "SELECT ID,City,State FROM [WorkSheet3$]";





                                //using (OleDbCommand cmd = conn.CreateCommand())
                                // {


                                using (OleDbDataReader reader = cmd.ExecuteReader())
                                {
                                    while (reader.Read())
                                    {
                                        Console.WriteLine(reader["WorkSheet1"].ToString());
                                        Console.WriteLine(reader["WorkSheet2"].ToString());
                                        Console.WriteLine(reader["WorkSheet3"].ToString());
                                    }

                                }
                            }
                                Console.Read();
                            //}
                        }


                }

                catch (Exception ex)
                {
                    Label1.Text = "ERROR: " + ex.Message.ToString();
                }
            }
            else
            {
                Label1.Text = "Upload Valid File!";
            }
        }
        else
        {
            Label1.Text = "You have not specified a file.";
        }

 }




}

have this code for reading multiple tag form excelsheet when i debuging code it not goes in following part

while (reader.Read())
 {
 Console.WriteLine(reader["WorkSheet1"].ToString());
 Console.WriteLine(reader["WorkSheet2"].ToString());
 Console.WriteLine(reader["WorkSheet3"].ToString());
 }
 }
 }

and gives following errors No value given for one or more required parameters.
if correct the above code