What do I need to run a jar-file?

Hello!What do I need to have installed to run a jar file?Thanks.
[85 byte] By [Markus1982a] at [2007-10-1 21:09:05]
# 1
You need the Java Runtime Environment installed: http://java.sun.com/downloads/index.html
derelict.pta at 2007-7-13 3:06:27 > top of Java-index,Desktop,Deploying...
# 2

I have it installed and it just says:

Could not find main class. Program will exit.

But if I start it on another Pc (the same jarfile) it works.

I have also installed the JDK, but it still doesn't work

and I checked the manifest file of the jar file and it is ok.

(it says main-class: ......)

Markus1982a at 2007-7-13 3:06:27 > top of Java-index,Desktop,Deploying...
# 3

I'm not sure if this entry is case sensitive but at Sun documentation it is allways uses the form:

Main-Class: classname

It is also provided the following warning:

The text file must end with a new line or carriage return. The last line will not be parsed properly if it does not end with a new line or carriage return.

--

Domingo Sebastian

http://www.prestigevillas.com

dominicusa at 2007-7-13 3:06:27 > top of Java-index,Desktop,Deploying...