function* getIndex(indexList){

  var len = indexList.length;

  var m;

    while(indexList.length > 0){

    m = Math.floor(Math.random()*len+1);

    var n = indexList.indexOf(m);

    // console.info(n +" "+indexList);

    if(n >= 0){

          yield m

          indexList.splice(n,1);

    }

    }

    return m;

}