Check For Null

In my code below where it says convert from data and time to just date...how do i check full null values?
Dim dv2 As DataView = CType(Sqlupdate.Select(DataSourceSelectArguments.Empty), DataView) If dv2.Count > 0 Then Dim ii As Integer = 0 Do Until ii = dv2.Count Dim dr2 As DataRowView = dv2.Item(ii) 'txtlocationid.Text = dr.Item(0).ToString txtpgname.Text = dr2.Item(1).ToString txtmaddr1.Text = dr2.Item(2).ToString txtmaddr2.Text = dr2.Item(3).ToString txtmaddr3.Text = dr2.Item(4).ToString txtmcity.Text = dr2.Item(5).ToString ddlstate2.Text = dr2.Item(6).ToString txtmzip.Text = dr2.Item(7).ToString txtctnm.Text = dr2.Item(8).ToString txtcemail.Text = dr2.Item(9).ToString ddlecommerce.Text = dr2.Item(10).ToString ...