Need help for animation in typing game

Hello Seniors,

I am posting this again and I hope I will get some guidance from you people. I am trying to develop a dynamic typing game. Below is the code I found from somewhere. It takes the movieclip on the stage from different directions. The problem with this code is that each time it brings the movieclip on the stage it changes its angle. I only need to bring the movieclip from different directions (I will put the text in these movieclips)

onEnterFrame = function(){

moveBox(box);}

function moveBox(rotatetext){

var speed:Number = 15;

if (rotatetext._x >= Stage.width+15) {

rotatetext._x = -10;

rotatetext._rotation = Math.random()*360;

}

if (rotatetext._x <= -15) {

rotatetext._x = 560;

rotatetext._rotation = Math.random()*360;

}

if (rotatetext._y <-20) {

rotatetext._y = Stage.height+20;

rotatetext._rotation = Math.random()*360;

}

if (rotatetext._y >= Stage.height+15) {

rotatetext._y = -15;

rotatetext._rotation = Math.random()*360;

}

rotatetext._x += speed//* Math.sin(rotatetext._rotation*(Math.PI/180));

rotatetext._y += speed//* Math.cos(rotatetext._rotation*(Math.PI/180));

}