running a jar file on desktop

hey i created a jar file using jgrasp and saved it in my documents, however when i click on it to launch it i get the message 'invalid or corrupt jarfile' what could be the problem?
[190 byte] By [kenana] at [2007-11-26 9:20:49]
# 1

Hi,

I would recommend to test jar file via zip command. If jar file is correct you must

be able to unzip it. This will exclude damage on filesystem level. When this is all

right I recommend to check JVM versions. Are they same during creation in

jgrasp and during the launch on your desktop. Please let me know your

findings.

PetrG at 2007-7-6 23:52:21 > top of Java-index,Development Tools,Java Tools...