javascript not working in a few systems on visualforce

Question

I have made an assessment portal using visualforce pages and sites. It is something that is a mock DEV401 exam. But I am facing a problem. At the end of the test, when user submits his test, a confirm box is rendered using javascript 'onClick'. Most of the times, it accepts the user response perfectly, but sometimes, even if the user clicks 'OK', the page does not navigate to the next page that shows the result, but rather refreshes the current page where the timer resets to 90 minutes again. Can anyone please tell me what must be going wrong in it?

Thanks in advance!

Answer 1

Ensure that the onClick event is prevented from bubbling up - that would submit your form and cause the page refresh.

If you are using a "simple" onclick (inline HTML attribute or jsElement.onclick = function (){}) then is enough to ensure the function is always returning a "false" value. (See https://stackoverflow.com/questions/128923/whats-the-effect-of-adding-return-false-to-an-onclick-event )

If you are using jQuery - $(el).click(function (e){}) - then you can add in your event block code e.preventDefault() and e.stopPropagation() to prevent event to bubble up to parent elements, or cause other effects than the ones you want in your logic. (See http://api.jquery.com/event.preventdefault/ and http://api.jquery.com/event.stoppropagation/). But even in jQuery case, returning false should be enough maybe.