Dataset Issue

Hi all,
 
m having problem with the following code:

ProtectedSub Page_Load(ByVal sender AsObject, ByVal e As System.EventArgs) HandlesMe.Load
        Dim a AsNew DataSet1.TasksDataTable()
        Dim adp AsNew DataSet1TableAdapters.TasksTableAdapter
        adp.Fill(a)
        GridView1.DataSource = a
        GridView1.DataBind()
        GridView1.Visible = TrueEndSub 

 
I created a dataset in visual studio by drag n drop. It has got two tables: Tasks and Reply. I saved the dataset by name Dataset1.xsd.
 
The problem is that the gridview doesn't show up at all. without throwing any errors.
please help. :(