web service server and client 1

on the server:

using System.Web.Services;
using System.EnterpriseServices;

[WebMethod(TransactionOption=TransactionOption.RequiresNew)]
  public DataSet GetData()
  {
   Trace.Write("Hello ....");

   TraceSwitch tsInfo = new TraceSwitch("acctInfo", "Info traces");
   tsInfo.Level = TraceLevel.Verbose;
   Trace.WriteLineIf(tsInfo.TraceVerbose, "XYZ");
//   Trace.WriteLineIf(tsInfo.Level > TraceLevel.Warning, "AAAA");

   this.sqlDataAdapter1.Fill(this.dataSet11);
   return dataSet11;
  }

  [WebMethod(EnableSession=true, MessageName="GetNo1")]
  public int GetNo()
  {
   Session["No"] = (int)Session["No"] + 1;
   return (int)Session["No"];
  }

  [WebMethod(EnableSession=true, MessageName="GetNoN")]
  public int GetNo(int n)
  {
   Session["No"] = (int)Session["No"] + n;
   return (int)Session["No"];

  }

on the global.asax.cs
  protected void Session_Start(Object sender, EventArgs e)
  {
   Session["No"] = 0;
  }

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if you want to enable the transaction

WebMethod(TransactionOption=TransactionOption.RequiresNew