<button class="btn btn-default" type="button" pd_options="org_airport=$val(origin_airport{{prefix}});dest_airport=$val(destination_airport{{prefix}})">
   <pd_script type="preRun">
       if ($("#origin_airport{{prefix}}").val() == "" || $("#destination_airport{{prefix}}").val() == ""){
           alert("Please select an origin and destination airport");
           return false;
       }
       return true;
   </pd_script>
      Analyze
   </button>
