$("select[data-variant-option-name='Panel']").on('change', function(e){
$this = $(this);
var options = $this.find('option');
var idx = options.index(options.filter(":selected"));
if($('.ProductItem-gallery :nth-child('+idx+')').length > 0)
$('.ProductItem-gallery :nth-child('+idx+')').click();
});
});
