nodes, you need to add
    COMMENT_NODE: 8,    // other constants here.
    DOCUMENT_NODE: 9,
    DOCUMENT_FRAGMENT_NODE: 11
  }
} 


var KEY_PAGEUP   = 33;
var KEY_PAGEDOWN = 34;
var KEY_END      = 35;
var KEY_HOME     = 36;

var KEY_LEFT     = 37;
var KEY_UP       = 38;
var KEY_RIGHT    = 39;
var KEY_DOWN     = 40;

var KEY_SPACE    = 32;
var KEY_TAB      = 9;

var KEY_BACKSPACE = 8;
var KEY_DELETE    = 46;
var KEY_ENTER     = 13;
var KEY_INSERT    = 45;
var KEY_ESCAPE    = 27;

var KEY_F1        = 112;
v