Tempory TABLE in vb.net with Gridview

Private Function temptable()
Dim dtcart As New DataTable
dtcart.Columns.Add("PID", Type.GetType("System.Int32"))
dtcart.Columns.Add("quantity", Type.GetType("System.Int32"))
dtcart.Columns.Add("amount", Type.GetType("System.Double"))
dtcart.Columns.Add("price", Type.GetType("System.Double"))
dtcart.Columns.Add("prdname", Type.GetType("System.String"))
dtcart.PrimaryKey = New DataColumn() {dtcart.Columns("pid")}
Dim lblamount As Double
Dim pid As Int32
Dim qty As Int32
Dim price As Double
Dim prdname As String
Dim i As Int32
For i = 0 To GridView1.Rows.Count - 1
'lblamount = CType(GridView1.Rows.Item(i).FindControl("Label7"), Label).Text
lblamount = CType(GridView1.Rows.Item(i).FindControl("Label6"), Label).Text * CType(GridView1.Rows.Item(i).FindControl("qty"), TextBox).Text
pid = CType(GridView1.Rows.Item(i).FindControl("Label2"), Label).Text
qty = CType(GridView1.Rows.Item(i).FindControl("qty"), TextBox).Text
price = CType(GridView1.Rows.Item(i).FindControl("Label6"), Label).Text
prdname = CType(GridView1.Rows.Item(i).FindControl("Label1"), Label).Text
Dim row As DataRow = dtcart.NewRow
row("PID") = pid
row("quantity") = qty
row("amount") = lblamount
row("price") = price
row("prdname") = prdname
dtcart.Rows.Add(row)
Next
Session("dtcart") = dtcart
End Function




If Session("abc") Is Nothing Then
Dim dtCart As New DataTable()
dtCart.Columns.Add("PID", Type.GetType("System.Int32"))
dtCart.Columns.Add("quantity", Type.GetType("System.Int32"))
dtCart.PrimaryKey = New DataColumn() {dtCart.Columns("pid")}
Session("abc") = dtCart
End If

Private Function grdbind()
Dim dt As New DataTable
dt = Session("abc")
GridView1.DataSource = dt
GridView1.DataBind()



End Function