function randNum(){
  var l = arguments.length;
  var f = -1;
  var c = -1;
  switch (l){
    case 1:
      f = 0;
      c = arguments[0];
      break;

    case 2:
      f = arguments[0];
      c = arguments[1];
      break;

    default:
      f = -1;
  }
  if (f >= 0){
    var r = Math.random();
    var d = c - f;
    var rnd = r * d;
    var rand = Math.round(rnd) + f;

  }
  return rand;
}