How many keys can be detected by ActionScript?

Hey, I'm using Flash 8 with AS2. I made a fighting game called ColorClash and the sequel, ColorClash 2.

If you play them (I'll give you links to them below), you'd know I'm fairly decent with programming AS. However, I came across a problem.

Sometimes in the game, when one player presses a few buttons like left arrow key and attack, while another player does another two keys, some keys will not function. I think the limit is like 3-4 keys. This makes it extremely frustrating, since it's a 2 player game.

I wanted to make a game similar to Super Smash Bros, but I knew this would be a problem. I want t have so many buttons, but the fact that only like 3 keys are aloud at a time is just dumb and it will ruin the whole game.

Is there a way to maximize the limit of keys? I'm using if (Key.isDown(##)){

Thanks.

By the way, here's the link to the games I made:
ColorClash - http://megaflash.weebly.com/uploads/...colorclash.swf
ColorClash 2 - http://megaflash.weebly.com/uploads/...lorclash_2.swf

Also, check out my Flash website:
http://megaflash.weebly.com/