Xyle

I appreciate the help. It being the work week, I didn't get a chance to really put some time into any solution and I definitely am not going to post the embarassing hack I was attempting.
I did get a plug and play solution involving some math equations that are quite a bit beyond me that I will post for anyone running into the same situation. It works great!

dawsonk
http://www.kirupa.com/forum/showthread.php?376083-Picking-Tile-in-staggered-isometric-map
Maybe try something like this...

    var tileW = 64;
    var tileH = 32;
    var rows = 8;
    var cols = 4;
    for (var i = 0; i < rows; ++i) {
		    for (var j = 0; j < cols; ++j) {
				    tTile = _root.attachMovie("Tile", "R" + i + "C" + j, _root.getNextHighestDepth());
				    tTile._x = (tileW * j) + ((i % 2 == 1) ? 32 : 0);
				    tTile._y = (tileH / 2) * i;
		    }
    }
    onMouseDown = function () {
		    var ax, ay, bx, by;
		    var cx = _xmouse;
		    var cy = _ymouse;
		    var posX = (_xmouse / 32) >> 0;
		    var posY = (_ymouse / 16) >> 0;
		    if ((posX % 2) == (posY % 2)) {
				    ax = (posX) * 32;
				    ay = (posY + 1) * 16;
				    bx = (posX + 1) * 32;
				    by = (posY) * 16;
				    if (getPos(ax, ay, bx, by, cx, cy) < 0) {
						    trace(((posY / 1 >> 0) - 1) + " : " + ((posX / 2 >>0) + ((((posY / 1 >> 0) - 1) % 2 == 0) ? 0 : -1)));
				    } else {
						    trace((posY / 1 >> 0) + " : " + (posX / 2 >> 0));
				    }
		    } else {
				    ax = (posX) * 32;
				    ay = (posY) * 16;
				    bx = (posX + 1) * 32;
				    by = (posY + 1) * 16;
				    if (getPos(ax, ay, bx, by, cx, cy) < 0) {
						    trace(((posY / 1 >> 0) - 1) + " : " + (posX / 2 >>0));
				    } else {
						    trace((posY / 1 >> 0) + " : " + ((posX / 2 >> 0) +((((posY / 1 >> 0) - 1) % 2 == 0) ? -1 : 0)));
				    }
		    }
    };
    function getPos($ax, $ay, $bx, $by, $cx, $cy) {
		    // below = 1, above = -1, on = 0;
		    var slope = ($by - $ay) / ($bx - $ax);
		    var yIntercept = $ay - $ax * slope;
		    var cSolution = (slope * $cx) + yIntercept;
		    if (slope != 0) {
				    if ($cy > cSolution) {
						    return $bx > $ax ? 1 : -1;
				    }
				    if ($cy < cSolution) {
						    return $bx > $ax ? -1 : 1;
				    }
				    return 0;
		    }
		    return 0;
    }

Thanks for the reply,

Looking to see which tile is clicked by the mouse using the mouse x,y coordinates. There isn't any offsets, so screen 0,0 is map 0,0.