Custom Post Type Query W/Category Dropdown

Question

I'm having a bit of trouble getting a custom post type query working coming from two drop downs. Let me show you what I'm using:

The Form:

<?php require($_SERVER['DOCUMENT_ROOT'] . '/wp-load.php'); ?>
<form method="post" id="searchform" action="http://www.findabuilder247.com/directory">

<?php $args = array(
   'show_option_none'   => 'Select a Tradesman',  
   'name'                => 'catagory',
   'post_type' => 'profiles',
   'hide_empty' => '1'
); ?> 

<?php wp_dropdown_categories( $args ); ?>

<?php $args = array(
   'show_option_none'   => 'Select Area',  
   'name'                => 'area',
   'show_count' => '1',
   'taxonomy' => 'areas',
   'orderby' => 'name',
   'post_type' => 'profiles',
   'hide_empty' => '1'
); ?> 

<?php wp_dropdown_categories( $args ); ?>

<input type="submit" value="" class="searchbutton4"  />
</form>

I'm then generating the query (or at least attempting to) with:

<?php 

 if($_POST){

     $query = $_POST;

     $cats = array();

      foreach($query as $key => $param) {

          if($param != -1) {

            array_push($cats, $param);

          }

      }

      // print_r($cats);  // This prints the array, so I know it's working

     query_posts(array( 'category__and' => $cats ));

 } ?>

I'm using a custom loop to call the query in initially and I'm hoping to use this as a search function.

 <?php $loop = new WP_Query( array( 'post_type' => 'profiles', 'posts_per_page' => 10, 'order'=> 'ASC', 'orderby' => 'title' ) ); ?>
    <?php while ( $loop->have_posts() ) : $loop->the_post(); ?>
        ...
    <?php endwhile; ?>

Any help would be much much appreciated. I'm pulling my hair out at this!

UPDATE

James Kemp is an absolute master! The following code is working perfectly for me:

<?php $loop = new WP_Query( array( 'post_type' => 'profiles', 'posts_per_page' => 10, 'order'=> 'ASC', 'orderby' => 'title' ) ); ?>
    <?php 

     if($_POST){

         $query = $_POST;

         $cats = array();

         foreach($query as $key => $param) {

             if($param != -1) {

               array_push($cats, $param);

             }

         }

         $args=array(
           'category__in' => $cats,
           'post_type' => 'profiles',
           'posts_per_page' => 10,
           'order'=> 'ASC',
           'orderby' => 'title'
           );
         $loop= null;
         $loop = new WP_Query($args);

     } ?>

     <?php while ( $loop->have_posts() ) : $loop->the_post(); ?>
             …
             <?php endwhile; ?>

Answer 1

You seem to be using 2 separate queries there, the first (query_posts) won't do anything, and the second is the query that will be used. Have you tried:

$args=array(
  'category__in' => $cats,
  'post_type' => 'profiles',
  'posts_per_page' => 10,
  'order'=> 'ASC',
  'orderby' => 'title'
  );
$loop= null;
$loop = new WP_Query($args);

Try that instead of:

query_posts(array( 'category__and' => $cats ));

and

<?php $loop = new WP_Query( array( 'post_type' => 'profiles', 'posts_per_page' => 10, 'order'=> 'ASC', 'orderby' => 'title' ) ); ?>