How to identify Netscape 6 browsers with JavaScript

The JavaScript code that we used to identify browsers is generally as follows:

<script language= "JavaScript" >
<!--
if (document.all) {//ie
Alert ("Your browser is Internet Explorer");
}
else if (document.layers) {//ns
Alert ("Your browser is Netscape Navigator");
}
else {
Alert ("Cannot detect your browser");
}
-->
</SCRIPT>

The above code can work well in Netscape6, and now when you use Netscape6, it will pop up the "Browser not detected" information, that is, can not correctly identify the Netscape6.
This is because Netscape 6 does not support document.all and does not support document.layers. Netscape 6 supports document.getElementById. But IE also supports
This method, so the instrumentation code must be rewritten to accommodate Netscape6.

Here is the detection code:

<script language= "JavaScript" >
<!--
if (document.all) {//ie
Alert ("Your browser is Internet Explorer");
}
else if (document.layers) {//ns
Alert ("Your browser is Netscape Navigator");
}
else if (document.getElementById) {//increase this row to detect whether Netscape 6
Alert ("Your browser is Netscape 6");
else {
Alert ("Cannot detect your browser");
}
-->
</SCRIPT>