 
     isControlKey = (which) ->
       controlKeys.indexOf(which) >= 0
+
+    isInertKey = (which) ->
+      inertKeys.indexOf(which) >= 0
 
     invalidInput = (elem, event) ->
       invalidKey(event) or invalidZero(elem, event)


    # 0 = tab, 8 = backspace , 13 = enter, 46 = delete, 37 = left arrow, 39 = right arrow
    controlKeys = [0,8,13, 46, 37, 39] 
    keyCodes = { 48:0, 49:1, 50:2, 51:3, 52:4, 53:5, 54:6, 55:7, 56:8, 57:9 }

    getOptions = (scope, attrs) ->


            elem.on 'keydown', (event) ->
              keycode = event.which

              killEvent(event) unless isInertKey(keycode)

              return if invalidInput(elem, event)
              # unless isControlKey(keycode)
