CreateChildSymbol on the top left bottom right edges of the window/stage?

Question

I am creating a particle system and I am trying to generate the particles / CreateChildSymbol on the top left bottom right edges of the window/stage?
Currently I am generating random X & Y points but thats not really doing what I need.
// find the stage width & height
sym.maxWidth = $('#Stage').width();
sym.maxHeight = $('#Stage').height();
// randomize the numbers 1-12
var randomSymbol = Math.floor((Math.random()*12)+1);
// Pull symbol from lib and add to stage
sym.mainParticle = sym.createChildSymbol("symbol_ani_" + randomSymbol, "Stage");
// create jQuery object / Edge Ani element var
sym.mainParticleElement = sym.mainParticle.getSymbolElement();
// randomize the stage X & Y coords
var randomX = Math.floor(Math.random() * sym.maxWidth);
var randomY = Math.floor(Math.random() * sym.maxHeight);
// position  based on random stage X + Y position
sym.mainParticleElement.css({'position':'absolute','top':randomY+'px','left':randomX+'px'} );
But I am at a loss of how to randomize the top / right / bottom / left X & Y edges of the stage

Answer 1

Got it working!
Well to be honest another friend helped me work out the logic for randomizing the sides (top, left, bottom, right) to get it working.
But I wanted to share since I had a hard time finding anything releated to this topic. Big Ups to Resdesign + Tim Jaramillo for helping me with some logic along the way as well!
// these variables are global within compReady would need to change to sym. instead of var if needed outside of this
var moveToX = $(window).width()/2,
     moveToY = $(window).height()/2;
function spawnParticle() {
     // these variables are only availabe inside this function
     var side = Math.floor(Math.random() * 4),
         offScreen = 100,    // how many pixels off the side of the screen to start
         yRand = Math.floor(Math.random() * $(window).height()),
         xRand = Math.floor(Math.random() * $(window).width()),
         xPos = 0,
         yPos = 0;
     switch (side) {
         case 0:
             xPos = xRand;
             yPos = -offScreen;
             console.log('spawn from top');
         break;
         case 1:
             console.log('spawn from right');
             xPos = $(window).width() + offScreen;
             yPos = yRand;
         break;
         case 2:
             console.log('spawn from bottom');
             xPos = xRand;
             yPos = $(window).height() + offScreen;
         break;
         case 3:
             xPos = -offScreen;
             yPos = yRand;
             console.log('spawn from left');
         break;
     // add to the stage
     sym.mainParticle = sym.createChildSymbol("star", "Stage");
     sym.mainParticleElement = sym.mainParticle.getSymbolElement();
     sym.mainParticleElement.css({'position':'absolute','top':yPos+'px','left':xPos+'px'});
     // simple animation to reveal the particle
     sym.mainParticleElement.animate({ left: moveToX, top: moveToY }, 1000, function() {
         // for this test, I'm removing the particle after it has finished animating
         $(this).fadeOut(function() {
             $(this).remove();
// keep spanwing new particles
setInterval(spawnParticle, 500);