function submitSearch(keyword) {

      alert(JSON.stringify({'tags':JSON.stringify(searchTags)}));

     $.ajax({
         type: "POST",
         url: "search-tags.php",
         data:JSON.stringify({'tags':JSON.stringify(searchTags)}),
         processData: false,
         contentType: "application/json",
         beforeSend: function(html) {
             $('#searchModal').foundation('reveal', 'close');
             $("#searchResults").html('');
             $("#homeScreen").hide();
             $("#resultsScreen").show();
             //$("#searchPhrase").html("Tag: " + searchString);
         },
         success: function(html){
             $("#searchResults").show();
             $("#searchResults").append(html);
         },
         error: function(html){
             alert("Error in search.");
             $("#searchResults").append(html);
         }
     });

    return false;
};


<?php
   //error_log(json_decode($_POST, true));
   //error_log($_POST[0]);
   print_r(count($_POST));

?>