How I can set the width and height of a JavaScript alert box?

JavascriptWeb DevelopmentFront End Technology

To set the width and height of an alert box in JavaScript, you need to use the custom alert box. This alert box is styled with CSS.

Set the width and height of the alert box using the following code, which uses jQuery, a JavaScript library −


<!DOCTYPE html>
      <script src="">
         function functionAlert(msg, myYes)
            var confirmBox = $("#confirm");
            display: none;
            background-color: #F3F5F6;
            color: #000000;
            border: 1px solid #aaa;
            position: fixed;
            width: 300px;
            height: 100px;
            left: 50%;
            margin-left: -100px;
            padding: 10px 20px 10px;
            box-sizing: border-box;
            text-align: center;
         #confirm button {
            background-color: #FFFFFF;
            display: inline-block;
            border-radius: 12px;
            border: 4px solid #aaa;
            padding: 5px;
            text-align: center;
            width: 60px;
            cursor: pointer;
         #confirm .message
            text-align: left;
      <div id="confirm">
         <div class = "message">This is a warning message.</div><br>
         <button class="yes">OK</button>
      <input type="button" value="Click Me" onclick="functionAlert();" />
Published on 01-Feb-2018 11:56:44