Search + Sum + GridView + Edit

[met0555]

Hi,

I changed some line of code.... and using this code, i'm able to see the edit mode gridview but i have to click twice the button to go to the edit mode and the edit textboxes are blank.
Still even when it's blank i tried to edit rows value i get the following error

Object reference not set to an instance of an object.

at this line

dt.Rows(row.DataItemIndex)("client") = (CType((row.Cells(4).Controls(0)), TextBox)).Text

current code

Protected Sub GridView1_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs)
        '  Dim GridView1 As GridView
 
        Dim GridView1 As GridView = TryCast(LoginView1.FindControl("GridView1"), GridView)
        GridView1.EditIndex = e.NewEditIndex
 
 
    End Sub
 
    Protected Sub GridView1_PageIndexChanging(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewPageEventArgs)
        Dim GridView1 As GridView = TryCast(LoginView1.FindControl("GridView1"), GridView)
 
        GridView1.PageIndex = e.NewPageIndex
       
    End Sub
    Private Sub BindData()
        Dim GridView1 As GridView = TryCast(LoginView1.FindControl("GridView1"), GridView)
 
        GridView1.DataSource = Session("trackmain")
        GridView1.DataBind()
    End Sub
 
    Protected Sub GridView1_RowCancelingEdit(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCancelEditEventArgs)
        Dim GridView1 As GridView = TryCast(LoginView1.FindControl("GridView1"), GridView)
 
        GridView1.EditIndex = -1
 
    End Sub
 
    Protected Sub GridView1_RowUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs)
        Dim GridView1 As GridView = TryCast(LoginView1.FindControl("GridView1"), GridView)
 
        Dim dt = CType(Session("trackmain"), DataTable)
 
        'Update the values.
        Dim row = GridView1.Rows(e.RowIndex)
        dt.Rows(row.DataItemIndex)("client") = (CType((row.Cells(4).Controls(0)), TextBox)).Text
 
        GridView1.EditIndex = -1
 
 
    End Sub
End Class

thanks