buttons enabled/not enabled problem

I have a problem making a flash rpg game. I was reading many tutorials but I cant seem to do it correctly. I will appreciate any help!

This should work as follows: I have 100 hours to do some things like work, study etc. and each of these actions will reqire 1 hour to complete. After there will be 0 hours left, the buttons required for performing "work", "study" etc should be disabled.
Problem: When I reach 0 hours, it then start to count hours left upwards! 1,2,3...

This is the code:
// Variables
var money:Number = 0;
var hours:Number = 16;

//Button name :"work" (other buttons will have similar code)
on (release) {
money += 100,,
hours -= 1;
}

//Buttons enabled/disabled
if (hours < 1) {
work._alpha = 50;
work.enabled = false;
} else {
work._alpha = 100;
work.enabled = true;
}

Once again thanks for any help or suggestions!

One way to do this is to use a single function for handling deductions from your time pool.

code:

---

ModifyHours = function(amt)

{

  hours += amt;

  if (hours <= 0) {

    // disable time-related buttons here

    work._alpha = 50;

  }

  else {

    // enable time-related buttons here

    work._alpha = 100;

  }

}

---

This is a common programmer's trick and is called a 'bottleneck' function - the idea is to get all the processing for hours to pass thru that one point.

Then your individual button handlers look like this:

code:

---

on (release) {

  if (hours > 1)

  {

    money += 100,,

    ModifyHours(-1);

  }

}

---

Then, if there's a way to increase the time pool, you would use something like:

ModifyHours(1);

Thanks for quick reply! Everything working now:)