Create a number of radio buttons based on an attr.

Is it possible to create a number of  radio button s based on an attr? For example if HP was 10 the number of buttons would also be ten.

No. But if you know the maximum number of HP any character could have, you could create that number of radio buttons on the sheet and use CSS to hide those that should not be shown at the current value of HP

Great idea but that wont work since the maximum number is so flexible in GURPS

If you have the HP arranged in blocks like that, it does seem doable. You basically have one set of bottons going up to whatever the reasonable max is in GURPS (20? 25?), and then have that copied 5 more times. (for <0, <-1x , <-2x, etc). But it seems a bit overkill to do HP like that for GURPS - characters shouldnt be dropping below 0 HP that often, and once they are that low, they are often out of action till they recover. A simple number box seems more practical.

Have you met my players?