First, If you want to show the mouse:
Code:
mouse_mode = 2; //not =1.


and for the space:
Code:
if (key_space) // not key_s; that's the "S" letter.
{
     c_move (my, vector(-20*time_step, 0, 0), nullvector, GLIDE);
     ent_animate(my,"run",walk_percentage, ANM_CYCLE);
     walk_percentage += 10 * time_step;
}