Many a times, IE7 stands out from the group of modern web-browsers owing to its notorious incompatibility with many a standard HTML/CSS/JS. In this article, we are seeing the following case of incompatibility: CSS border for Select (Drop down) element does not work.
On one of my Drupal sites, while validating a form, when a required input field has not been filled before hitting the Submit button, an error message is shown, and the field is highlighted with a red border. The red border was achieved with this CSS: