code: function pickup (/*len, dict || dict */) {
  	var str = '', pos;
  	var len, dict;
  
  	if (arguments.length === 1) {
  		dict = arguments[0];
  		len = 1;
  	} else if (arguments.length === 2) {
  		len = arguments[0];
  		dict = arguments[1];
  	} else {
  		return string();
  	}
  
  	for (var i=0; i< len; i++) {
  		pos = dice(dict.length - 1);
  		str += dict.substring(pos, pos + 1);
  	}
  
  	return str;
  }
docs: dict is a string