Math random help

programming flash
1

Hey there

I am making a game where red squares spawn on the right side of the screen. So far the red squares spawn all the way up and down the height of the stage.

The problem is that i want the red squares to spawn only in areas randomly below a certian height of the stage

This is the code so far

enemy.x = 470 ;
                enemy.y = Math.random() * stage.stageHeight;

This code makes the red squares spawn all the way up and down the height of the stage

Thanks for any help