Creating Pop-up Notes with CSS and JavaScript Part II

We’ve gone a long way to make sure that our scripts works with multiple pop-up notes, and is useful when working with modern browsers. However, what about older browsers, or current browsers with JavaScript turned off? What about people with disabilities who use a screen reader? Considering that the number of people that fall under any of these categories is small, it’s still a strong reason to use JavaScript code prudently. Regarding this particular example, if JavaScript is turned off, the rest of the Web page content will still work, even without the notes. But it’s strongly recommended to use pop-up notes to provide additional information. Sensitive and critical information should always be presented to the users in the safest way possible.

Before we go deeper into the code, it’s valid to consider that when we’re working with CSS and JavaScript, browser incompatibility issues might come up. So, it’s always advisable to perform a browser checking process to generate the proper code, in order to determine which version of the Document Object Model (DOM) to use, which is often associated with the old browsers.

var ns4=document.layers; // Nestcape 4

var ie4=document.all;  // Internet Explorer 4

var nn6=document.getElementById && ! document.all; // Nestcape 6

if(ns4){
            // code for Netscape 4 goes here
}
else if(ie4){
            // code for Internet Explorer 4 goes here
}
else if(nn6){
            // code for Nestcape 6 goes here
}

Keep browser compatibility issues in mind when creating pop-up notes. I hope you've found these articles useful.