[Windows Mobile Software Development] Archer:
It's because the variable itmTXTbox1 is declared within the Load method, so only that method has access to it. You need to declare it at a higher level within the class if you want to give other class methods access to it....

Imports StedySoft.SenseSDK
Imports StedySoft.SenseSDK.DrawingCE

Public Class frmTables

Dim _processEntireButton As Boolean = True
Dim _buttonAnimation As Boolean = False

'declare form controls here so they have global scope
Dim itmMore As StedySoft.SenseSDK.SensePanelMoreItem
Dim itmTXTbox1 As StedySoft.SenseSDK.SensePanelTextboxItem
Dim itmTXTbox2 As StedySoft.SenseSDK.SensePanelTextboxItem
Dim hdr As StedySoft.SenseSDK.SensePanelDividerItem

Private Sub frmTables_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load

'set the list scroll fluidness
Me.senseListCtrlTables.Velocity = 0.75F

'turn off UI updating
Me.senseListCtrlTables.BeginUpdate()

' add SensePanelItem(s) w/o thumbnail image
hdr = New StedySoft.SenseSDK.SensePanelDividerItem()
hdr.Text = "Select Table"
Me.senseListCtrlTables.AddItem(hdr)

' add SensePanelMoreItem(s)
itmMore = New StedySoft.SenseSDK.SensePanelMoreItem
itmMore.ProcessEntireButton = Me._processEntireButton
itmMore.PrimaryText = "Select Table"
itmMore.SecondaryText = "No Table selected yet!"
itmMore.Tag = "Tag1"

' add SensePanelRadioItem(s) in Child Container
Dim arrayTables1 As New System.Collections.ArrayList()
arrayTables1.Add("Table 1")
arrayTables1.Add("Table 2")
arrayTables1.Add("Table 3")

' add SensePanelRadioItem(s) in Child Container
Dim arrayTables2 As New System.Collections.ArrayList()
arrayTables2.Add("Lenght")
arrayTables2.Add("Weight")
arrayTables2.Add("Volume")

Dim j As Integer = 0
Do While (j <= 2)
Dim itm As StedySoft.SenseSDK.SensePanelRadioItem = New StedySoft.SenseSDK.SensePanelRadioItem
itm.ProcessEntireButton = Me._processEntireButton
itm.PrimaryText = arrayTables1(j)
itm.SecondaryText = arrayTables2(j)
itm.Tag = arrayTables1(j)
itm.GroupName = "RadioGroup1"

AddHandler itm.OnStatusChanged, AddressOf Me.OnRadioStatusChanged
itmMore.Children.Add(itm)
j = (j + 1)
Loop
Me.senseListCtrlTables.AddItem(itmMore)

hdr = New StedySoft.SenseSDK.SensePanelDividerItem()
hdr.Text = "Results"
Me.senseListCtrlTables.AddItem(hdr)

' added 2 textbox
itmTXTbox1 = New StedySoft.SenseSDK.SensePanelTextboxItem
itmTXTbox2 = New StedySoft.SenseSDK.SensePanelTextboxItem

itmTXTbox1.LabelText = "Current Table:"
itmTXTbox1.Text = ""
itmTXTbox1.ShowSeparator = False
itmTXTbox1.ReadOnly = True

itmTXTbox2.LabelText = "Category:"
itmTXTbox2.Text = ""
itmTXTbox1.ReadOnly = True

Me.senseListCtrlTables.AddItem(itmTXTbox1)
Me.senseListCtrlTables.AddItem(itmTXTbox2)

'we are done so turn on UI updating
Me.senseListCtrlTables.EndUpdate()

End Sub

Private Sub OnRadioStatusChanged(ByVal Sender As Object, ByVal Status As SensePanelRadioItem.ItemStatus)
Dim itm As StedySoft.SenseSDK.SensePanelRadioItem = CType(Sender, SensePanelRadioItem)
CType(Me.senseListCtrlTables.ParentFocusedItem, SensePanelMoreItem).SecondaryText = ("Current selection is " + itm.Tag.ToString)

itmTXTbox1.Text = itm.PrimaryText
itmTXTbox2.Text = itm.SecondaryText

End Sub

End Class

I'm not a VB coder, so I'm not 100% sure that's correct syntax, but if it's not then I'm sure you'll get the idea anyway.

Hope this helps mate :)