Recognizing multiple key presses in As3

Question

Hi,
I have a simple game with three keyboard inputs - left, right and fire
I want to be able to log when a key is pressed and released. In the game, you can be in the following states:
None
Left only - keyz on the keyboard
Right only - keyc on the keyboard
Fire only - keyx on the keyboard
Left and Fire - keyz and Keyx on the keyboard
Right and Fire - Keyc and Keyx on the keyboard
When Left key is pressed for example, it should log LeftKeypressStart and when it is released, it shoul log leftKeyPressStop. The same should happen to Right and Fire keys when they are pressed individually.
Now, for the game to be in  Left and Fire state either of the three conditions are true:
Left key can be pressed and held down before the fire button is pressed and held down or
Fire button is pressed and held down before left is pressed and held down or
Both keys pressed down simultenuosly (although this condition will rarely occur as we are not robots)
Similar conditions should be true for the game to be in the Right and Fire State
Now considering the first condition,when Left key is down, I want the game to log LeftKeypressStart but as soon as the Fire key is down, it should log LeftKeyPressStop and also Log LeftandFireKeypressStart. Then if Fire is released first, I want it to log LeftandFirKeypressStop and then log LeftKeyStart. but if Left is released first, it should log  LeftandFirKeypressStop and then lof FireKeyPressStart.
This is what I have at the minute:
private function onKeyPress (evt:KeyboardEvent)
if (evt.keyCode == 67 && evt.keyCode !=88 && evt.keyCode != 90)
//log Right  
else if (evt.keyCode != 67 && evt.keyCode !=88 && evt.keyCode == 90 )
//log Left
else if (evt.keyCode != 67 && evt.keyCode !=90 && evt.keyCode == 88)
//log Fire
else if (evt.keyCode == 67 && evt.keyCode !=90 && evt.keyCode == 88 )
//log RF
private function onKeyRelease(evt:KeyboardEvent)
if (evt.keyCode == 67 && evt.keyCode !=88 && evt.keyCode != 90)
//stop right
else if (evt.keyCode != 67 && evt.keyCode !=88 && evt.keyCode == 90 )
//stop Left
else if (evt.keyCode != 67 && evt.keyCode !=90 && evt.keyCode == 88)
//stop Fire
else if (evt.keyCode == 67 && evt.keyCode == 88  && evt.keyCode !=90 )
// stop RF    

Answer 1

There can only be one evt.keyCode per keypress, so your approach will not work.  All you need to do is determine which key caused the function to execute.  If you want to keep track of which keys are down, just create three Boolean variables, as in...
var leftDown:Boolean = false;
var rightDown:Boolean = false;
var fireDown:Boolean = false;
and set those values to true or false and make use of them in whatever other code you intend.
private function onKeyPress (evt:KeyboardEvent)
if (evt.keyCode == 67)
             rightDown = true  
else if (evt.keyCode ==88)
             leftDown = true
else if (evt.keyCode == 88)
             fireDown = true
// process per whatever values are true/false
and in the key up function set them back to false in a similar fashion.