Hey guys, I've got a complex block of PHP/Javascript that isn't functioning. I'm trying to manipulate a form that contains 4 dropdown select lists. Each dropdown is dependent upon what was selected in the one above it. I apologize for the huge amount of code, but I was hoping someone might be able to spot a syntax error or something else simple that I'm missing.
The form in question is located in the right sidebar of the following site: http://www.buyautocovers.com
 $Manufacturer_array[] = array('id' => 'all', 'text' => $this->__('Choose Make'));
$Model_array[] = array('id' = 'all', 'text' = $this-('Choose Model'));
 $Number_array[] = array('id' = 'all', 'text' = $this-('Choose Year'));
 $Body_array[] = array('id' = 'all', 'text' = $this-__('Choose Body Type'));
$javascript = '
 //
var a = new Array();
 var b = new Array();
 var c = new Array();
 var d = new Array();';
$M_a = array();
foreach ($rows as $r) {
if (!isset($M_a [$r['manufacturer']]))
    $Manufacturer_array[] = array('id' = $r['manufacturer'], 'text' = $r['manufacturer']);
$M_a [$r['manufacturer']][$r['model']][$r['number']][$r['body']] = 1;
 }
$i = 0; 
 foreach ($M_a as $k =$v){
  $javascript .= 'a['.$i.']="'.$k.'";b['.$i.'];c['.$i.'];=new Array(';
   $ii = 0;
   $s = '';
   foreach ($M_a[$k] as $kk =$vv){
    $javascript .= ($ii != 0 ? ',' : '').'"'.$kk.'"';
    $ss = '';
    $iii = 0;
    foreach ($M_a[$k][$kk] as $kkk = $vvv){
     $javascript .= ($iii != 0 ? ',' : '').'"'.$kkk.'"';
     $sss = '';
     $iiii = 0;
      foreach ($M_a[$k][$kk][$kkk] as $kkkk = $vvvv){
       $sss .= ($iiii != 0 ? ',' : '').'"'.$kkkk.'"';
       $iiii++;
      }
     $ss .= 'd['.$i.']['.$ii.']['.$iii.']=new Array('.$sss.');';
     $iii++;
    }
    $s .= 'd['.$i.']['.$ii.']=new Array('.$ss.');';
    $ii++; 
   }
  $javascript .= ');d['.$i.']=new Array();'.$s; 
  $i++; 
 }
$javascript .= '
  function pop_model(){
var o ="' . $this-('Choose Model') . '"; 
   var sv = $(\'mmn_manufacturer\').value;
   if(sv != "all"){
    var v = a.length;
    while(v--) if(sv == a[v]) break;
    for(var i = 0; i < b[v].length; i++)
      o+=""+b[v][i]+"";
   }
   o+="";
   $(\'model_select\').innerHTML= o;
      $(\'number_select\').innerHTML= "' . $this-('Choose Year') . '";
  }
function pop_number(){
var o ="' . $this-('Choose Year') . '";
   var sv = $(\'mmn_manufacturer\').value;
   if(sv != "all"){
    var v = a.length;
    while(v--) if(sv == a[v]) break;
    var sv2 = $(\'mmn_model\').value;
     if(sv2 != "all"){
      var v2 = b[v].length;
      while(v2--) if(sv2 == b[v][v2]) break; 
      for(var i = 0; i < c[v][v2].length; i++)
       o+=""+c[v][v2][i]+"";
     }
   }
   o+="";
   $(\'number_select\').innerHTML= o;
   $(\'body_select\').innerHTML= "' . $this-('Choose Body Type') . '";
  }
function pop_body(){
var o ="' . $this-__('Choose Body Type') . '";
   var sv = $(\'mmn_manufacturer\').value;
   if(sv != "all"){
    var v = a.length;
    while(v--) if(sv == a[v]) break;
    var sv2 = $(\'mmn_model\').value;
     if(sv2 != "all"){
      var v2 = b[v].length;
      while(v2--) if(sv2 == b[v][v2]) break; 
      var sv3 = $(\'mmn_number\').value;
       if(sv3 != "all"){
        var v3 = c[v].length;
        while(v3--) if(sv3 == b[v]c[v2][v3]) break; 
        for(var i = 0; i < d[v]c[v2][v3].length; i++)
         o+=""+d[v]c[v2][v3][i]+"";
       }
     }
   }
   o+="";
   $(\'number_select\').innerHTML= o;
  }
  //]]
  ';
$expire = time()+60*60*24*90;
if (isset($_GET['Manufacturer'])){
  setcookie("Manufacturer_selected", $_GET['Manufacturer'], $expire,'/');
  if ($_GET['Manufacturer'] != 'all')
   $Manufacturer_selected_var = $_GET['Manufacturer'];
 } elseif (isset($_COOKIE['Manufacturer_selected']) && $_COOKIE['Manufacturer_selected'] != 'all') 
  $Manufacturer_selected_var = $_COOKIE['Manufacturer_selected'];
if (isset($_GET['Model'])){
  setcookie("Model_selected", $_GET['Model'], $expire,'/'); 
  if ($_GET['Model'] != 'all')
   $Model_selected_var = $_GET['Model'];
 } elseif (isset($_COOKIE['Model_selected']) && $_COOKIE['Model_selected'] != 'all')
  $Model_selected_var = $_COOKIE['Model_selected'];
if (isset($_GET['Number'])){
  setcookie("Number_selected", $_GET['Number'], $expire,'/');
  if ($_GET['Number'] != 'all')
   $Number_selected_var = $_GET['Number'];
 } elseif (isset($_COOKIE['Number_selected']) && $_COOKIE['Number_selected'] != 'all')
  $Number_selected_var = $_COOKIE['Number_selected'];
if (isset($_GET['Body'])){
  setcookie("Body_selected", $_GET['Body'], $expire,'/'); 
  if ($_GET['Body'] != 'all')
   $Body_selected_var = $_GET['Body'];
 } elseif (isset($_COOKIE['Body_selected']) && $_COOKIE['Body_selected'] != 'all')
  $Body_selected_var = $_COOKIE['Body_selected'];
if (isset($Manufacturer_selected_var) && isset($M_a[$Manufacturer_selected_var]))
  foreach ($M_a[$Manufacturer_selected_var] as $k => $v)
$Model_array[] = array('id' = $k, 'text' = $k);
 if (isset($Manufacturer_selected_var) && isset($Model_selected_var) && isset($M_a[$Manufacturer_selected_var][$Model_selected_var]))
      foreach ($M_a[$Manufacturer_selected_var][$Model_selected_var] as $k = $v)
  $Number_array[] = array('id' = $k, 'text' = $k);
 if (isset($Manufacturer_selected_var) && isset($Model_selected_var) && isset($Number_selected_var) && isset($M_a[$Manufacturer_selected_var][$Model_selected_var][$Number_selected_var]))
      foreach ($M_a[$Manufacturer_selected_var][$Model_selected_var][$Number_selected_var] as $k = $v)
  $Body_array[] = array('id' = $k, 'text' = $k);
echo $javascript;