Cleaner walljumping code

wj = 0
if place_free(x,y +1)
{
    gravity_direction = 270
    gravity = 0.5
    if !place_free(x+move_speed,y)
    {
	if move_speed>0
        {
            wj = 1
        }
        else
        {
            wj = 2
        }
    }        
}
else
{
    gravity = 0
}
if place_free(x +move_speed,y)
{
    x = x +move_speed
}
if !keyboard_check(vk_left) and !keyboard_check(vk_right) and wj = 0
    {
        sprite_index = spr_b_1
        move_speed-=1*sign(move_speed)
    }