My 2 cents

gistfile1.js

// global scope
(function(){
    // outer scope
    var fibonacci = function(){
        my_return = "0, ";
        current_number = 0;
        minus_one_order = 0;
        minus_two_order = 0;
        max_order=12;
        for(current_order = 1;current_order<=max_order;current_order+=1){
            if(current_order===1){
                current_number = 1;
            }
            else{
                current_number = minus_one_order+minus_two_order;
            }
            minus_two_order = minus_one_order;
            minus_one_order = current_number;
            my_return += current_number.toString()+(current_order<max_order?', ':'');
        }
        return my_return;
    }
    console.info(fibonacci());
})();

// global scope
 
(function(nth){
 
 // outter scope
 
 var fibonacci = function(max_order){
     max_order = max_order==null?12:max_order;
     current_number = 0;
     minus_one_order = 0;
     minus_two_order = 0;

     for(current_order = 1;current_order<=max_order;current_order+=1){
         if(current_order===1){
             current_number = 1;
         }
         else{
             current_number = minus_one_order+minus_two_order;
         }
         minus_two_order = minus_one_order;
         minus_one_order = current_number;
     }
     return current_number;
 }
 console.info(fibonacci(nth));
 // the call below is going to have a result with the position
 // 2x ahead of the one passed to nth
 console.info(fibonacci(nth*2));
})(10);