SSL problem

Hi all,
I have installed Zoho Virtual Office on a Slackware 10.2 machine. The Installation run successfully and I could connect over http successfully, too. But using Zoho Virtual Office requires the connection over https. I have configured the https corresponding to the instruction under the help menu. That means I have generated the key using keytool and copied the key file into the <Zoho Virtual Office Home>/server/default/conf directory. After that I have edited the server.xml and entered the name of the appropriate key file and replaced the password.

But if I try to establish the https connection I get the error message "The connection was refused when attempting to contact localhost:8443". Must I configure my apache web server in any way? Could anybody give me a hint what the problem could be?

Regards
Andrea