Lode Runner version 2.11a, AI_VERSION=4

(1) Modified for AI VERSION = 4
   (1.1) When guard failing in hole, will drop gold before guard failing into hole totally
   (1.2) Shake time extension when guard in hole.
         NOW the runner can dig three hold for three guards and pass through them. (MUST quickly)
	 ==> The behavior almost same as original lode runner (APPLE-II version).
   Modified files: LodeRunner/lodeRunner.guard.js

(2) New Demo Data all ai_version = 4
    modified files: lodeRunner.demoData1.js

(3) Slow down play speed:
                            //slow normal fast
    change from speedMode = [15, 20, 25, 30, 35];
             to speedMode = [14, 18, 23, 29, 35];
    Modified files: lodeRunner.main.js

(4) Keep ai version don't overflow:
    Modified files: lodeRunner.preload.js

lodeRunner.preload.js

@@ -420,14 +420,15 @@ function createSoundInstance()
 var spriteSpeed = [
 	{ runnerSpeed: 0.65, guardSpeed: 0.3,  digSpeed: 0.68, fillSpeed: 0.24, xMoveBase: 8, yMoveBase: 8 }, //ver 1
 	{ runnerSpeed: 0.70, guardSpeed: 0.35, digSpeed: 0.68, fillSpeed: 0.27, xMoveBase: 8, yMoveBase: 9 }, //ver 2
-	{ runnerSpeed: 0.8,  guardSpeed: 0.4,  digSpeed: 1,    fillSpeed: 1,    xMoveBase: 8, yMoveBase: 9 }  //ver 3 
+	{ runnerSpeed: 0.8,  guardSpeed: 0.4,  digSpeed: 1,    fillSpeed: 1,    xMoveBase: 8, yMoveBase: 9 }  //ver 3 & 4 
 ];
 
 var curAiVersion = AI_VERSION;
 var maxGuard = MAX_NEW_GUARD; 
 function setSpeedByAiVersion()
 {
-	var speedObj = spriteSpeed[curAiVersion-1];
+	var idx = (curAiVersion > spriteSpeed.length)?(spriteSpeed.length-1):(curAiVersion-1); //array index don't overflow
+	var speedObj = spriteSpeed[idx];
 	
 	RUNNER_SPEED = speedObj.runnerSpeed;
 	GUARD_SPEED = speedObj.guardSpeed;