Follow Up Can one change the appearance of the alert/confirm/prompt box? The default Alert box can be customized (or over-ridden) by JavaScript + CSS. But the drawback is to verify the compatibility on different browsers. See the following: http://slayeroffice.com/code/custom_alert/ http://www.gayadesign.com/diy/customize-the-default-alert-function-of-javascript/ http://www.codeproject.com/Articles/28812/Custom-Alert-Boxes-using-JavaScript-and-the-DOM • Final Answer • 1. not possible with HTML • 2. not possible with CSS • 3. possible with quite a lot of JavaScript code What is the Meaning of === in JavaScript?