Avoid Cursor within a bound box

Hello,

I'm working on a game for a course I'm taking and I need an object to avoid the cursor, but so far, it only moves down!

import flash.events.MouseEvent;
var stageLeft = 15;//left boundary
var stageRight = 285;//right boundary
var stageTop = 40;//top boundary
var stageBottom = 185;//bottom boundary
var mPositionX = stage.mouseX; //sets horizontal margin 20
var mPositionY = stage.mouseY; //sets vertical margin 20
var moveLeft = - 1; //left movement
var moveRight = 1; //right movement
var moveTop = - 1; //top movement
var moveBottom = 1; //bottom movement
var speed:int = 5; //speed
butterfly_mc.addEventListener(MouseEvent.MOUSE_MOVE, avoidCursor);
function avoidCursor(evt:MouseEvent) {
    var middle:int =  butterfly_mc.width/2;
    butterfly_mc.x += speed; 
    butterfly_mc.y += speed; 
    trace('x: '+mouseX+', y:'+mouseY);
    trace('m: '+middle);
    if (butterfly_mc.x <= stageLeft){
        butterfly_mc.x += speed * moveRight;
    } else if (butterfly_mc.x >= stageRight){
        butterfly_mc.x += speed * moveLeft;
    } else if (butterfly_mc.x == stageRight){
        butterfly_mc.x += speed * moveLeft;
    }
    if (butterfly_mc.y <= stageTop){
        butterfly_mc.y += speed * moveBottom;
    } else if (butterfly_mc.y >= stageBottom){
        butterfly_mc.y += speed * moveTop;
    } else if (myButterfly.y == stageBottom){
        butterfly_mc.y += speed * moveTop;
    }
}

Any idea what I might be doing wrong here? Super confused!

ETA: I realized after I posted I was very vague on the purpose of the game.  I need to accomplish certain things in certain ways to obtain credit here.  The butterfly needs to avoid the mouse   pointer when the pointer is within 20 pixels of the butterfly.