I've been working on a project which has involved finding the values or setting the values on controls (label, dropdownlist etc.) embedded inside of other other controls (repeater, gridview etc.). You have to drilldown or look inside the parent object containing these controls to make this work. This is where the Page.FindControl method comes in useful. Here are some examples:
Dim lb As LinkButton = sender
If Not (lb Is Nothing) Then
'Get the value for a dropdownlist using Parent.FindControl
Dim strDirRace As String = CType(lb.Parent.FindControl("ddlDirRace"), DropDownList).SelectedItem.Text
'Get the value for a dropdownlist specifying the name of repeater control housing it
Dim strDirRace As String = CType(rptDirectorDetails.FindControl("ddlDirRace"), DropDownList).SelectedItem.Text
Dim lblDirRace As Label = CType(lb.Parent.FindControl("lblDirRaceUpdateStatus"), Label)
lblDirRace.Text = "* Update Complete *"
End If When you use a Master page, then you need to do this
Dim cbx As CheckBox = CType(Master.FindControl("Content1").FindControl("cbxAllTel"), CheckBox)
More info on this topic: http://msdn2.microsoft.com/en-us/library/31hxzsdw.aspx