You have two issues.
1) You need to pass the runtime into your function jumpPowerBarRun. It should be jumpPowerBarRun(runtime)
2) using runtime.objects.JumpPowerBar. That doesn't return an object for you to work with. It gives you access to functions to get instances that exist in your layout
You would have to do something like runtime.objects.JumpPowerBar.getAllInstances() or runtime.objects.JumpPowerBar.getFirstInstance(). When you get all you will have to loop through them, but get first returns the object so you could then do runtime.objects.JumpPowerBar.getFirstInstance().width.
There are other methods that you can use