Why doesnt my frostwire want to work?

I clicked on it to download music and it tells me "Frostwire was unable to load The Java Runtime Environment. Please download and install a newer version from a href="http://www.java.com"" rel="nofollow"http://www.java.com"/a How do i do this..I went to the java website but its just so confusing how do i know which one to download?