Hi there I am having problems changing the backgrounf colour of a mobile textbox at runtime

This is my code

Protected Sub oblstRec_ItemSelect(ByVal sender As Object, ByVal e As System.Web.UI.MobileControls.ObjectListSelectEventArgs) Handles oblstRec.ItemSelect
Me.ActiveForm = frmRes
lblpartn.Text = e.ListItem.Item("PartNumber")
txtpartn.Text = e.ListItem.Item("PartName")
txtcon.Text = e.ListItem.Item("Condition")
txtloc.Text = e.ListItem.Item("Location")
txtquan.Text = e.ListItem.Item("Quantity")
txtval.Text = e.ListItem.Item("Valid")
If (txtval.Text = 0) Then
Me.txtval.BackColor = Drawing.Color.Aqua
Else
Me.frmRes.BackColor = Drawing.Color.Green
End If
End Sub

It tests if the data reterived for the txtval textbox is 0, if it is it should change the background coloyr to aqua and if not green
It does nothing, yet if i change the textbox name to the form name it will change the form background with this code just not the text box background
Anyone have any ideas it is driving me nuts
lee