Bootstrap popover content cannot changed dynamically

If you grab the popover instance like this:

var popover = $('.reply').data('bs.popover');

Then, to redraw the popover, use the .setContent() method:

popover.setContent();

I found out browsing the source: https://github.com/twitter/bootstrap/blob/master/js/popover.js

So, in your example, try:

thisVal.attr('data-content',data).data('bs.popover').setContent();

Update

The setContent() method also removes the placement class, so you should do:

var popover = thisVal.attr('data-content',data).data('bs.popover');
popover.setContent();
popover.$tip.addClass(popover.options.placement);

Demo: http://jsfiddle.net/44RvK