There are times you need to know what controls are on your page. You might test them for example on page init or page load.
This is how you print out all the controls on the page.
Press Submit to see what controls are on this page - if you try entering some text below or checking the checkbox, you will see the control values too

Public Sub CheckControls(ByVal Container As Object)

        'call like this CheckControls(Page) to iterate through all controls (or just pass in a more specific object)

        'write straight to page - bit old fashioned - could build a string and set a label.text

        Response.Write("<br>" & Container.ID & " controls are ... <br>")

        Dim ctl As Control

        For Each ctl In Container.Controls

            Response.Write("&nbsp;&nbsp;&nbsp;") 'indent

            If ctl.HasControls Then 'be thorough, iterate child controls

                CheckControls(ctl)
            End If

            If TypeOf ctl Is CheckBox Then 'pick out specific types and display properties of interest

                Dim ChkBox As CheckBox

                ChkBox = ctl
                Response.Write("<b>ChkBox=</b>" & ChkBox.ID & "  checked=" & ChkBox.Checked)

            ElseIf TypeOf ctl Is TextBox Then 'show it's ID and text values

                Dim TxtBox As TextBox

                TxtBox = ctl
                Response.Write("<b>TextBox=</b>" & TxtBox.ID & "  text=" & TxtBox.Text)

            Else 'just show it's ID

                'Response.Write(ctl.ID & "|")

            End If

        Next

    End Sub

Here's the code...

     Public Sub CheckControls(ByVal Container As Object)
        'call like this CheckControls(Page) to iterate through all controls (or just pass in a more specific object)
								'write straight to page - bit old fashioned - could build a string and set a label.text
		Response.Write("
")
        Dim ctl As Control
        For Each ctl In Container.Controls
			If ctl.HasControls Then	'be thorough, iterate child controls
				CheckControls(ctl)
			End If
			If TypeOf ctl Is CheckBox Then 'pick out specific types and display properties of interest
				Response.Write(Container.ID & " controls are ... 
")	'indent
				Dim ChkBox As CheckBox
				ChkBox = ctl
				Response.Write("ChkBox=" & ChkBox.ID & "  checked=" & ChkBox.Checked)
				Response.Write(vbCrLf)
			ElseIf TypeOf ctl Is TextBox Then	'show it's ID and text values
				Response.Write(Container.ID & " controls are ... 
")	'indent
				Dim TxtBox As TextBox
				TxtBox = ctl
				Response.Write("TextBox=" & TxtBox.ID & "  text=" & TxtBox.Text)
				Response.Write(vbCrLf)
			Else 'just show it's ID
				'Response.Write(ctl.ID & "|")
			End If
		Next
		Response.Write("
")
    End Sub