Radiobuttons

I’m sorry for being such a n00b question,

But how do I get the flash file to recognise the value of each radio button?

I’m using these variables:

[For a menu to chose the difficulty of the game]

data = easy
groupName = difficulty
label = Easy
labelplacement = Right
selected = false

Instance name = easy

data = medium
groupName = difficulty
label = Medium
labelplacement = Right
selected = false

Instance name = medium

data = hard
groupName = difficulty
label = Hard
labelplacement = Right
selected = false

Instance name = hard

Thats one menu line, the buttons work, as in if you select one and change it, they change correctly, but I dont know how I can code it to get the right values.

What I want to do, is to get the player to chose a difficulty to give a _global. variable which I can then use throughout the program so I can refer to it, and change other values in the game using this value.

Will I also need some sort of button that saves the data within the program temporalily, or will it be fine just with a back button?

http://www.activatejapanese.com/Chavs2/bomberman_x.swf

Thats the link for what i’ve got so far.

Thanks in advance