20-2.html

来自「js 全的样例代码,比较适合大家学习和交流」· HTML 代码 · 共 18 行

<!-- Check whether JavaScript 1.2 is supported. -->
<script language="JavaScript1.2">var _js12_ = 1.2</script>

<!-- Now avoid the problems with JavaScript 1.2 on Netscape by running -->
<!-- the following code on any browser that supports JavaScript 1.1. If -->
<!-- the browser does not support JavaScript 1.2, however, we'll display -->
<!-- an error message and suppress any syntax errors that occur. -->
<script language="JavaScript1.1">
// If JavaScript 1.2 is not supported, fail gracefully.
function supressErrors() { return true; }
if (!_js12_) {
    window.onerror = supressErrors;
    alert("This program requires a browser with JavaScript 1.2 support");
}

// Now proceed with the JavaScript 1.2 code. 
</script>