Java webstart

Hey how can I enable java webstart on my webspace?

I read on sun that there should be a file called mime.types somewhere and that I just had to add the following line for making it work.

application/x-java-jnlp-file JNLP

If this is true where should this file be located? (tried to make one in the root but it didn’t workout)

Is there another way to enable webstart?

I found a thread about .htacess or what the file was called, and jnlp was also already added to dh’s mime types. It seems it was an error in my firefox, it worked all along in IE.