Vista - radiobuttums groupbax tabpage

Hi,

i've a problem to save the value of a radiobuttum in a groupbox on a winform
with multiple tabpages. when i place the groubox out of the tabpage i come
into my procedure of radiobuttumclicked eg " CType(sender,
RadioButton).Parent.Tag = sender.tag"

when i place the groupbox into a tabpage i cannot reach the
radiobuttumclicked ??
i'v mad my program in Visual Basic 2005 .
grtz Klaas