[FlashCS4/AS2]Need to switch clips and shoot

I’m trying to make a small simple horizontal shooter game and I want to switch out my player_mc to my playershoot_mc and then make the playershoot_mc shoot a bullet, the switch and the shooting i want to occur simultaneously when I hit the space bar. Having difficulty first off getting the movie clip to switch and then to get it to shoot. help? will post code (took out my bullet attempts to make it shorter…it failed to say the least haha)

var speed=3;

function playerMove() {
    if (Key.isDown(Key.LEFT)){
        player_mc._xscale !=-100;
    if (Key.isDown(Key.RIGHT)){
        player_mc._xscale != 100;
    if (Key.isDown(Key.SPACE)){
        player_mc.attachMovie("shoot", "shoot_mc", 1);

setInterval(playerMove, 10);