diff --git a/Three.js/js/KeyboardState.js b/Three.js/js/KeyboardState.js
index 673af8f..cc3506d 100644
--- a/Three.js/js/KeyboardState.js
+++ b/Three.js/js/KeyboardState.js
@@ -10,6 +10,8 @@
  *       keyboard.down("A")    -- true for one update cycle after key is pressed
  *       keyboard.pressed("A") -- true as long as key is being pressed
  *       keyboard.up("A")      -- true for one update cycle after key is released
+ * (4) cleanup keyboard event listeners when you no longer need them
+ *       keyboard.destroy();
  * 
  *  See KeyboardState.k object data below for names of keys whose state can be polled
  */
@@ -22,6 +24,14 @@ KeyboardState = function()
 	document.addEventListener("keyup",   KeyboardState.onKeyUp,   false);	
 }
 
+// cleanup - stop listening to key events
+KeyboardState.prototype.destroy = function()
+{
+	// unbind keyEvents
+	document.removeEventListener("keydown", KeyboardState.onKeyDown, false);
+	document.removeEventListener("keyup",   KeyboardState.onKeyUp,   false);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 KeyboardState.k = 
@@ -109,4 +119,4 @@ KeyboardState.prototype.debug = function()
 	console.log(list);
 }
 
-///////////////////////////////////////////////////////////////////////////////
\ No newline at end of file
+///////////////////////////////////////////////////////////////////////////////