Implement a For loop in MooTools

I have to use Mootools for a website but being a real newbie I'm stuck with my code:

  var val = element.get('value');
  // Here I get a number between 1 and 6 and I'd like to implement a loop that goes from 1 to the value of val (between 1 and 6) 
  $('jj_enfant' + val).addClass("validate['required']");
  $('mm_enfant' + val).addClass("validate['required']");
  $('aaaa_enfant' + val).addClass("validate['required']");开发者_运维问答
  $('last_name_enfant' + val).addClass("validate['required','nodigit']");
  $('first_name_enfant' + val).addClass("validate['required','nodigit']");

var val = element.get('value').clean().toInt();

for (var ii = 1; ii <= val; ++ii) {
    $('jj_enfant' + ii).addClass("validate['required']");
    $('mm_enfant' + ii).addClass("validate['required']");
    $('aaaa_enfant' + ii).addClass("validate['required']");
    $('last_name_enfant' + ii).addClass("validate['required','nodigit']");
    $('first_name_enfant' + ii).addClass("validate['required','nodigit']");
}

// or... 

while(val--) {
    $('jj_enfant' + val).addClass("validate['required']");
    $('mm_enfant' + val).addClass("validate['required']");
    $('aaaa_enfant' + val).addClass("validate['required']");
    $('last_name_enfant' + val).addClass("validate['required','nodigit']");
    $('first_name_enfant' + val).addClass("validate['required','nodigit']");
}

This isn't a Mootools question, just a javascript question.

for (var counter = 1; counter < val; counter++) {
    //Loop code
}