I need to dynamically change 2 select fields by using a little math and php (a JS solution would be fine too.).

**Example:** I'm booking a trip...

* I can have 8 travelers total.
* 1 traveler needs to be an adult
* The rest can be 7 kids if needed

**Adult select field:**

```
@for($adults = 1; $adults<=8; $adults++)
   <option value="{{ $adults }}">{{ $adults }}</option>
@endfor

```

Based on the Adults number value, this needs to reflect how many Kid spots are left.

**Kids select field:**

```
@for($kids = 0; $kids <= 8 - $step->adults; $kids++)
    <option value="{{ $kids }}">{{ $kids }}</option>
@endfor

```

So some quick examples:

* 1 adult = 0-7 kids
* 2 adults = 0-6 kids
* 3 adults = 0-5 kids
* 4 adults = 0-4 kids
etc..

This is a multi-step form and I'm currently storing everything in a session/cookie. As I have it now, the Kids logic only works if I hit the continue button. *(Not ideal)*

> 
> How can I get the Kids to update immediately based on the Adults value
>  before I continue to the next form.
> 
> 
> 

I'm currently using Laravel / PHP, but a JS solution would be acceptable if needed.

I would appreciate any help.