how do I tell if java is installed ?

Hi,

I am a newbie and now very literate in all things apple. I have a macbook air and have been having lots of trouble loading internet pages. Some are very very slow to load, and others won't load at all. I checked the software update and it said everything was up to date.

I manually went to Java.com to check i had latest version and it said I was missing a plug in and it directed me to update to the latest Java version. Tried to to this but it won't load at all. Gets to about 16.6mg of 52 (odd) mg and just times out or something, but it won't load.

I went to apple/applications/utilities but can't see Java there at all. Don't know why this is, but I'm the first to admit I'm hopeless at these things.

Any suggestions on what I should do next ?

Thanx for your help