Hello,
You can use some javascript with or without jquery. I don't know how you can activate something after a flash effect, but here is an example with :
Waiting an image loafing
Waiting 5 seconds
Move to next question.
I using this script:
<script type="text/javascript" charset="utf-8">
$(document).ready(function() {
$("input.submit").hide();
$("#imageload").load(function() {
$('#movesubmit').val('movesubmit');
window.setTimeout(function() {
$('#limesurvey').submit();
}, 5000)
});
});
</script>With the image identify by id="imageload".
You can hav a look at this demo :
demonstration.sondages.pro/27177 
