Question iterate through Dynamic controls

[vinelectronics]

I had created the dynamic controls by following code

pnlControls.Controls.Add(New LiteralControl("<Table>"))

'Page.Controls.Add(New LiteralControl("<Table>"))

For i = 0 To dt.Rows.Count - 1
CtrlType = dt.Rows(i)(1).ToString
CtrlName = dt.Rows(i)(2).ToString
CtrlText = dt.Rows(i)(3).ToString

Select Case CtrlType

Case "TextBox"
pnlControls.Controls.Add(New LiteralControl("<tr>"))
pnlControls.Controls.Add(New LiteralControl("<td>" & CtrlText & "</td>"))
pnlControls.Controls.Add(New LiteralControl("<td>"))
Dim box As New TextBox
pnlControls.Controls.Add(box)
box.ID = CtrlName
pnlControls.Controls.Add(New LiteralControl("</td>"))
pnlControls.Controls.Add(New LiteralControl("</tr>"))

Now i want to iterate through the controls and retrieve its values and store in database .

For Each ctrl In pnlControls.Controls
If ctrl.GetType().ToString.Equals("System.Web .UI Controls.TextBox") Then

End If
Next

but the above code doesn't finds any controls placed in the asp placeholder.

Kindly find me a solution ASAP.

Thanks in advance