gistfile1.java

class YourBody {
  boolean is_moving = false;
	String[] known_actions = { "Forward", "Backward", "Left", "Right" };
	
	boolean validRequest( String this_action ){
		for ( int i = 0; i < known_actions.length; i++)
		{
			if ( known_actions[i] == this_action )
			{
				return true;
			}
		}
		return false;
	}
	
	void MoveForward()
	{
		//move legs and stuff
	}

	void MoveBackward()
	{
		//move legs differently and that other stuff
	}
}

String request = "Forward";
if ( YourBody.validRequest( request ) )
{
	if ( request == known_actions[0] )
	{
		YourBody.MoveForward();
	}
} else {
print("I don’t understand that request...");
}