Usage:
radio_button(Handle, Parent, Radio_func, Text, X, Y, Width, Height)

Creates a radio button control.
 

Handle	handle. Use _ if you don't need it.
Parent	handle of the parent window. Use _ for default.
Radio_func	predicate which will receive edit messages
Text	the text on the control
X,Y	coordinates of upper left corner
Width, Height	size of the window

Look at radio button methods:

R is get_check_box_value(Radio_Button)
set_check_box_value(Radio_Button, Value)
 

See also:
window

Look at the example:
Radio Buttons.spj (in folder Examples)