How to move

if (keyboard_check(vk_left) || keyboard_check(ord("A")))
    {
    facing = 180;
    if (place_free(x-1,y))
        {
        x -= 4;
        }
    }
if (keyboard_check(vk_right) || keyboard_check(ord("D")))
    {
    facing = 0;
    if (place_free(x+1,y))
        {
        x += 4;
        }
    }
if (keyboard_check(vk_up) || keyboard_check(ord("W")))
    {
    facing = 90;
    if (place_free(x,y-1))
        {
        y -= 4;
        }
    }
if (keyboard_check(vk_down) || keyboard_check(ord("S")))
    {
    facing = 270;
    if (place_free(x,y+1))
        {
        y += 4;
        }
    }

if (keyboard_check(vk_space))
    {
    var o;
    o = instance_create(x,y,obj_bullet);
    o.speed = 12;
    o.direction = facing;
    }