problem getting values from cw_bgroup normal base

[redlmg98(at)hotmail.com (Lisa Gandy)]

I have set up a cw_bgroup in a normal base and am trying to get the 
individual values for each button.  This is the code that
I am using to set up the compound widget

main_bgroup_arr = ['one','two','three']
main_bgroup = cw_bgroup(base,main_bgroup_arr,/return_index,/column,$
              label_top='Main Menu',/frame,uvalue = 1)


and this is the code that I am using to try to access the individual
values for the buttons...

widget_control,main_bgroup,get_value=val.

The xmanager catches the error and says 
"unable to get plain button group value".

How do I get the individual values for each button?  Can I not
use the widget_control, get_value property??