Unable to retrieve dataset from the session

[whidbey]

Hello friends, I am whidbey, new to thescripts and dot net as well.I am working over Online Shopping Cart,web application.I design a page (webform5.aspx) where user search books then select the books to buy from the datagrid.
User can select books using checkboxes in the datagrid.

The selected books are stored in a session variable name session("temp") which is a dataset type.After storing dataset in session (in bold letters),user will redirected to next page "webform6.aspx" . Here is the code....

sub button2_click(sender as object,e as eventargs)
  'con.close()
  dim da as sqldataadapter,ds as dataset
  dim con as sqlconnection
  dim griditem as datagriditem
  dim kk as boolean
  dim row as integer
    con=new sqlconnection("server=WADHWA;user id=sa;pwd=;initial catalog=OnlineShoppingDatabase")
          con.open()
          da=new SqlDataAdapter()
          da.selectcommand=new SqlCommand()
          da.selectcommand.connection=con
          da.selectcommand.commandtext="insert temp_info values(@BookId,@CatId,@Title,@Author,@Publisher,@Price,@Quantity)"
          da.selectcommand.parameters.add(new sqlparameter("@BookId",SqlDbType.Int,0,"BookId"))
          da.selectcommand.parameters.add(new sqlparameter("@CatId",SqlDbType.Int,0,"CatId"))
          da.selectcommand.parameters.add(new sqlparameter("@Title",SqlDbType.varchar,10,"Title"))
          da.selectcommand.parameters.add(new sqlparameter("@Author",SqlDbType.varchar,10,"Author"))
          da.selectcommand.parameters.add(new sqlparameter("@Publisher",SqlDbType.varchar,10,"Publisher"))
          da.selectcommand.parameters.add(new sqlparameter("@Price",SqlDbType.float,0,"Price"))
          da.selectcommand.parameters.add(new sqlparameter("@Quantity",SqlDbType.Int,0,"Quantity"))
 
 
  for each griditem in datagrid1.items
   'chk=griditem.cells(0).findcontrol("checkbox")
   'kk=directcast(griditem.Cells(1).Controls(0), CheckBox).checked
da.selectcommand.parameters("@BookId").value=integer.parse(griditem.cells(8).text)
          da.selectcommand.parameters("@CatId").value=integer.parse(griditem.cells(9).text)
          da.selectcommand.parameters("@Title").value=griditem.cells(2).text
          da.selectcommand.parameters("@Author").value=griditem.cells(3).text
          da.selectcommand.parameters("@Publisher").value=griditem.cells(4).text
          da.selectcommand.parameters("@Price").value=decimal.parse(griditem.cells(5).text.Replace(" ", ""), Globalization.NumberStyles.AllowThousands or Globalization.NumberStyles.AllowCurrencySymbol or Globalization.NumberStyles.AllowDecimalPoint)
          da.selectcommand.parameters("@Quantity").value=integer.parse(griditem.cells(6).text)    
   kk=directcast(griditem.cells(0).findcontrol("checkbox1"),checkbox).checked
    if kk then
          'response.write("checked")
      row =da.selectcommand.executenonquery()
     end if
     row=0
    next  
     ds=new DataSet
    da.fill(ds,"temp_info")
    session("temp")=ds    
    'ds = nothing
    'da=nothing
    con.close()
    response.redirect("webform6.aspx")
  end sub

Then, I retrieve this dataset on the page load event of "webform6.aspx" .Here is the code.....

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        'If Not Page.IsPostBack Then
        If Session("temp") Is Nothing Then
            ds = New DataSet
            da = New SqlDataAdapter
            con = New SqlConnection("server=WADHWA;user id=sa;pwd=;initial catalog=onlineshoppingdatabase")
            con.Open()
            da.SelectCommand = New SqlCommand("select * from temp_info", con)
            da.Fill(ds, "temp_info")
            'DataGrid1.DataSource = ds
            'DataGrid1.DataSource = ds.Tables("temp_info")
            DataGrid1.DataBind()
        End If
        If Not Page.IsPostBack Then
            'DataGrid1.EnableViewState = False
            ds = New DataSet
            ds = CType(Session("temp"), DataSet)
            DataGrid1.DataSource = ds
            DataGrid1.DataBind()
        End If
    End Sub

But, I got an error :

Exception Details: System.Web.Http Exception: The IListSource does not contain any data sources.

But, I got an error :

Exception Details: System.Web.Http Exception: The IListSource does not contain any data sources.

Help me to remove this error and give me some good knowledge on this issue

[kenobewan]

Welcome to the site. Where do you use IListSource?

Please use code tags (# icon) as it makes your code easier to read. Thanks.