รบกวนหน่อยค่ะ งงมา 4 วันแล้ว (VB.net) เรื่อง กำหนดสิทธิ กับ Datagrid

Private Sub DataGridView1_CellMouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseUp
        Dim Rowindex As Integer
        If Rowindex = -1 Then Exit Sub
        With DataGridView1

            DetailDay.fname.Text = .Rows.Item(Rowindex).Cells(3).Value.ToString()
            DetailDay.Lname.Text = .Rows.Item(Rowindex).Cells(4).Value.ToString()
            DetailDay.Nname.Text = .Rows.Item(Rowindex).Cells(5).Value.ToString()
            DetailDay.Pname.Text = .Rows.Item(Rowindex).Cells(6).Value.ToString()
            DetailDay.Jname.Text = .Rows.Item(Rowindex).Cells(6).Value.ToString()
        End With

Dim sqlText = "select * from yourTable where username = 'xxxx' " 
Dim dtb As New DataTable
Dim dtAdapter As New SqlDataAdapter(sqlText, ConnectionString)
dtAdapter.Fill(dtb)

If dtb.rows.Count > 0
Dim usrClass = dtb.rows[0]["class"].ToString()
     If usrClass = "1" Then 
         'ถ้า user xxxx มีclass เป็น 1 จะเปิดปิดปุ่มยังไงก็ว่าไป
     Else If usrClass = "0" Then
         'ถ้า user xxxx มีclass เป็น 0 จะเปิดปิดปุ่มยังไงก็ว่าไป
     End If
End If

If dtb.Rows.Count > 0 Then
     Dim userclass = dtb.Rows(0)("Class").ToString()
   If userclass = "User" Then
     button1.enables = false
     button2.enables = true
   ElseIf userclass = "Admin" Then
     button1.enables = true
     button2.enables = false

   End If
End If