To check if someone has Java enabled?

is it possible?

[foy]

I'm searching for a possibility to check a surfers configuration about Java, not Javascript.

Is there a way I could do this via Javascript?
What about the cross browser compatibility, especially according to Netscape?

[BlobFisk]

There is the navigator.javaEnabled method that will allow you to test for this. It returns a Boolean value, so testing for it would use:

if ( navigator.javaEnabled() )
{
// Java is on
}

I read recently that this is reported incorrectly on Netscape 6.1 for Macintosh OS 9, always returning false. Seemingly it was fixed in Netscape 6.2 for Macintosh OS 9, but it is broken again in Netscape 7 PR 1 on OS 10.2 and Mozilla 1.1 on OS 10.2.