Help:P

Sorry for my bad title… but its hard to describe for me what I need help with:P

Hi guys, Im making a small race game and I have a couple questions;

Number one; If I’m having like three cars and three tracks, how can I ‘Load’ a specific action script? Because every car suppose to have different max speed, accel, etc.

Number two;
For another game (also a racing game I want to create a menu where you can choose you max speed, accel, by moving some bars, just like in this one;
http://www.solidworkspilot.com/

Lets just say I want to change;
accel = between 0.1 and 5
and
MAXspd = between 10 and 100

So how can I create that bar what can ‘change the script’

Ask if there is any information missing:P