// detection for Netscape
var useAcrobat = navigator.mimeTypes &&
navigator.mimeTypes["application/pdf"]
</SCRIPT>
<SCRIPT LANGUAGE="VBScript">
on error resume next
useAcrobat = not IsNull(CreateObject("AcroExch.Document"))
' can be CreateObject("PDF.PdfCtrl.1") too!
</SCRIPT>
<SCRIPT>
if (useAcrobat)
document.write("PDF 已安装");
else
document.write("未安装PDF");
</SCRIPT>