How to run jar files

[Marios K.]

Apo auto to site
http://simscience.org/crackling/Advanced/Earthquakes/EarthquakeSimulation.html
uuela na katebaso thn java efarmogh. Epedh otan ekana save th selida
stan html den katebaine to jar arxeio, psaxnontas sto ~.java/cache brhka
kapoia jar arxeia.
Otan omos ta trexo 
java -jar BlockApplet.jar
gyrnaei auto to munhma
Failed to load Main-Class manifest attribute from
BlockApplet.jar
Giati?