How to change Joomla Articles Navigation links to images

Which php page generates the Pre/Next links in articles, when I have enables "Show navigation" in the advanced parameters section for the menu assigned with the Articles开发者_运维知识库 of a particular category. Also how can I replace the Pre/Next button in articles to images? Thanks in advance.

You should not modify the joomla core code directly. To use images just add in the css file something like:

.prev{
background-image:url(images/prev.gif);
}

Also see this useful extension if it works for you: http://extensions.joomla.org/extensions/structure-a-navigation/site-navigation/13789

It'll be better to have prev/next page titles than arrow images.