Caching problem in asp.net

I am having problem in clearing the cache in asp.net. Below is my code in page load. My response string is and xml string. If i refresh my page then the xml output is not getting refreshed.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

  Try
     HttpResponse.RemoveOutputCacheItem("/spin.aspx")

     Dim strCardNo As String = Request.QueryString("CardNo")
     Dim strGame As String = Request.QueryString("GameName")
     Dim strPoints As String = Request.QueryString("Points")

     Dim strPointsPlayed As String = strPoints
     Dim intWin As Integer
     Dim winamount As Decimal = 0.0
     Dim gamewin As Decimal = 0.0

     objPhoneCard = CtblPhoneCard.GettblPhoneCardByID(strCardNo)
     objCustAc = CtblCustomerAccount.GettblCustomerAccountByCustomerID(objPhoneCard.AccountId)
     objCust = CtblCustomer.GettblCustomerByID(objCustAc.CustomerID)
     objCustBal = CtblCustomerBalance.GettblCustomerBalanceByID(objCustAc.CustomerID)

     Dim strOutPutXML As String = objSlotGame.GetSlotXML(strGame, Convert.ToInt32(strPoints), intWin)

     gamewin = intWin / 100

     '************************************************************************
     Dim dsWin As DataSet = CWebAPI.GetTicketsPlayed(CInt(strPointsPlayed))

     If Not IsNothing(dsWin) Then
         If dsWin.Tables.Count = 开发者_运维知识库1 Then
             If dsWin.Tables(0).Rows.Count > 0 Then

                 Dim drWin As DataRow
                 For Each drWin In dsWin.Tables(0).Rows
                     winamount = winamount + Convert.ToDecimal(drWin("Prize"))
                 Next
             End If
         End If
     End If

     CWebAPI.UpdateTicketStatus(CInt(strPointsPlayed))
     '************************************************************************

     objCustAc.Points = objCustAc.Points - CInt(strPointsPlayed)
     If CtblCustomerAccount.Update(objCustAc) Then
         objCustBal.PrizeAmount = objCustBal.PrizeAmount + gamewin
         objCustBal.BalanceAmount = objCustBal.BalanceAmount + gamewin
         If CtblCustomerBalance.Update(objCustBal) Then
             'strTotalSweeps = Convert.ToString(objCustAc.Points - CInt(strPointsPlayed))                
         End If
     End If

     Response.Write(strOutPutXML)

  Catch ex As Exception
     Response.Write(ex.Message)
  End Try


End Sub

Maybe this is not ASP.NET related but a behavior of the client caching the previous result?

What happens if you add some dummy querystring parameters to your web request? Like

http://.../....aspx?.....&dummy=1 

This is problem with my object creation. I found the source of the problem