A random DNI generator for testing purposes in JavaScript

random DNI generator

function formatNumberLength(num, length) {
  var r = "" + num;
  while ( r.length < length ) {
    r = "0" + r;
  }
  return r;
}

function charDNI(dni) {
  var chain = "TRWAGMYFPDXBNJZSQVHLCKET";
  var pos = dni % 23;
  var letter = chain.substring( pos, pos + 1 );
  return letter;
}

function rand_dni() {
  num = Math.floor( ( Math.random() * 100000000 ) );
  sNum = formatNumberLength( num, 8 );
  return sNum + charDNI( sNum );
}

Thanks mate!

Thanks :D