You might have better luck with this:

Code:
action move_tank()
{
  VECTOR speed;
  ANGLE rotAng;
  while(1)
  {
     rotAng.pan = 2 * (key_a - key_s) * time_step;
     c_rotate(my,rotAng,IGNORE_PASSABLE);
     speed.x = 10 * (key_w - key_s) * time_step;
     c_move(my,speed,nullvector,IGNORE_PASSABLE | GLIDE);
     wait(1);
  }
}


I was once Anonymous_Alcoholic.

Code Breakpoint;