importing packages from jar file

Hi all,I have a jar file that contain a package . And i set the clathpath with the path of jar file including the jar file name. And when I import the package i have an error that package does not exist. And I don't know why.
[240 byte] By [FCi-CSiana] at [2007-10-2 3:59:41]
# 1
1.) did you spell the path + name of the JAR file correctly?2.) Did you spell the package name including capitalization correctly?3.) Is the package hierarchie in the JAR the same as the package names?
MartinHilperta at 2007-7-15 23:21:33 > top of Java-index,Desktop,Deploying...
# 2
Yes.For simplicity , I changed the path of the jar file ( com.jar ) to "c:\" , then i added to the clathpath "c:\com.jar" , and again when I import the package the same error appear.
FCi-CSiana at 2007-7-15 23:21:33 > top of Java-index,Desktop,Deploying...