flash game softwareHow Can I Create My Own Flash Game? What Software Do I Need?

I remember a long time ago I had software to create flash games.
I know how to create a flash game, but flash game softwareI can't remember what software to use.

Was it Adobe Flash something?
I have Flash Player 10 but I want flash game softwareFlash Creator to make games.

Thanks in advance.
You have to buy it from Adobe and it is expensive!