jogendar 0 Light Poster

i have been searching about how to create an executable jar file,

http://csdl.ics.hawaii.edu/~johnson/613f99/modules/04/jar-files.html

by seing the above site i have created a jar file,while double clicking the jar file an error saying that
"jar file couldnt be loaded
check for possible console errors"
is being displayed,i had tried by downloading the actual jar file from the site too,but same error with that also,can anybody help me out...