 <p>Browsers render borders statically;</p> <p>About animating the border of a TextBox (presuming input:text or textarea) cross-borwser AND cross-platform is impossible. For a lesser scoped of browser, per say, modern browsers, there is css-level3 with <code>border-image</code>.</p> <p>But it will be painfull.</p> <p>About displaying a progress bar upon a TextBox, it will be quite easier, especially if your content is loaded via AJAX. It's all about a container displayed position absolute left top. Then the css animes the container.</p> <p>See jquery-ui or search the net for 'animated progess bar'</p>