Q:

two dependent dropdowns php arrays

I'm trying to substitute the code that uses javascript and arrays which are visible in source code.  
I want to be able to create this with php arrays, or use AJAX and have it stored in another file.  I don't know how to make the proper php commands or arrays 
var cars= new Array();

cars["OTHER"] = new Array("Heavy Machinery","Semi-Truck","Pickup Truck","Sedan","SUV","Misc");
cars["ATV"] = new Array("small","large");
cars["Boat"] = new Array("Under 20 Feet","Over 20 Feet");
cars["Motorcycle"] = new Array("250CC","500CC","700CC","900+");
cars["RV"] = new Array("Under 25 Feet","Over 25 Feet","5th Wheel");
cars["AC"] = new Array("Cobra");
cars["Acura"] = new Array("1.6 EL","1.7 EL","2.3 CL","2.5 TL","3.0 CL","3.2 TL","3.5 RL","CL","CSX","EL","ILX","Integra","Legend","MDX","NSX","NSX-T","RDX","RL","RSX","SLX","TL","TSX","Vigor","ZDX");
cars["Alfa Romeo"] = new Array("145","146","147","155","156","159","164","166","33","75","308","1900","2600","4C","6C","8C","Alfasud","Alfetta","Berlina","Bimotore","Canguro","Corsa","Disco Volante","Duetto","G1","GT","GTV","GTV-6","GTV6","Giulia","Guiletta","GP","Grand Prix","GTA","Iguana","Junior Z","Milano","Montreal","Navajo","P1","P2","P3","Quadrifoglio","RL","RM","Scarabeo","Spider","Sports Car","Sportwagon","Stradle","Tipo","Torpedo");
........................ALL OTHER MAKES AND MODELS ARE IN BETWEEN........................
cars["Yugo"] = new Array("55","Cabrio","GV");

jQuery(document).ready(function($){

$('span.text select').change(function(){
$(this).siblings('.value').text($(this).find('option[value="'+$(this).val()+'"]').text());
});

for ( make in cars )
{
$('#formmake').append('<option value="'+make+'">'+make+'</option>');
}

$('#formmake').change(function(){
var val = $(this).val();
$('#formmodel').html('<option value="">Select Model</option>');
for ( i in cars[val] )
{
$('#formmodel').append('<option value="'+cars[val][i]+'">'+cars[val][i]+'</option>');
}
$('#formmodel').append('<option value="Other">- Other -</option>');
});

$('#formmake, span.text select').each(function(){
var def = $(this).siblings('.value').text();
$(this).find('option[value='+def+']').attr('selected', 'selected');
$(this).change();
});

});

---------------------- this is what i want to do to HIDE the source on the site --------------------
here is my php to get the MAKE but how do I create the model array so that when a user chooses a car the appropriate MODELS will populate in the corresponding dropdown (called Select Model: )
<?php
    $car_make = array('ATV','Boat','Motorcycle','Acura','Alfa Romeo','AM              General');  //this is only a partial array, it will have all the makes

    echo '<select name="car_make">';
    for($i = 0; $i < count($car_make);$i++)
    {
        echo '<option value="'. ($i + 1) . '">' . $car_make[$i] . '</option>';
    }
    echo '</select>';

?>

how do i create a second array with vehicle models that will use the first array's option value to lookup a make and then pull the corresponding make's from the model array ?

A:

Well you can use jQuery to select the value of the first select menu and then use it to compare with the specific value for make and then display its specific models

var model=new Array();
function getmodel() {
var make=$('select[name=make]').val();
if(make==='toyota'){$("select[name=model]").html('');$("select[name=model]").append("<option value='corolla'>Corolla</option><option value='camry'>Camry</option><option value='hilux'>Hilux</option>");}

if(make==='honda'){$("select[name=model]").html('');$("select[name=model]").append("<option value='civic'>Civic</option><option value='jazz'>Jazz</option><option value='accord'>Accord</option>");}

if(make==='suzuki'){$("select[name=model]").html('');$("select[name=model]").append("<option value='cultus'>Cultus</option><option value='vitara'>Vitara</option>");}

if(make==='bugatti'){$("select[name=model]").html('');$("select[name=model]").append("<option value='veyron'>Veyron</option><option value='chiron'>Chiron</option>");}  
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
SELECT MAKE:
<select name='make' onchange='getmodel();'>
<option value='toyota'>TOYOTA</option>
<option value='honda'>HONDA</option>
<option value='suzuki'>SUZUKI</option>
<option value='bugatti'>BUGATTI</option>
</select>
<br/>
SELECT MODEL
<select name='model'>

</select>

