<OT> tcl/tk question: Radio buttons

[Joel Hammer]

I just want to get this point cleared up before I go off in the wrong
direction.

I have found if I change the global variable (-variable) associated with
a checkbutton, the button stops responding.

I have included a program snippet below, as I think you can't have
attachments on this list.

Basically, when I click a radio button, and run a command like 

     -command {puts "string"}

all works as expected. However, if I change the radiobutton option -variable
in the command, with something like:

     -command {set cb "You ran a program"}

the radio button stops responding. cb is my -variable in this radiobutton.

It makes no difference if I remove the -onvalue and -offvalue options.

Is this a bug or a feature or am I missing something?

Thanks,

Joel


#!/etc/alternatives/wish -f
frame .myframe2
pack .myframe2 -anchor w

# The command in the next line is the problem
checkbutton .myframe2.cb -text "Choice 2" -onvalue True -offvalue False -variable cb -command {set cb "You ran a program"}

# This next line works fine
# checkbutton .myframe2.cb -text "Choice 2" -onvalue True -offvalue False -variable cb -command {puts "You changed me"}

label .myframe2.lcb -textvariable cb 
pack .myframe2.cb .myframe2.lcb -side left