Tomcat Server - Urgent

I'm currently runnung Tomcat Server 3.3 on Win2k IIS 5.0
Here is the link :
http://www.hpbc.bdg.nus.edu.sg:8080/MSS/MSSNew.jsp

My Server is under a Local Network.

When I'm under that LAN, clicking on the link... it works fine
But whem I'm outside the LAN, ( means that from another ISP, and you guys also ), clicking on the link. It says that The page can not be displayed. ( you can try, and you will see )

It means that the Tomcat Server is not available ? But actually it works fine under the LAN. ( You can be sure of that point )
So, any one can help me figure it out. I spent 2 days already but can not find what the reason is.
And this is the web.xml of that Tomcat Server : http://www.hpbc.bdg.nus.edu.sg:8080/MSS/MSSNew.jsp

Thanks in advance,
With regards.

I think is your networking setting got problem. maybe you didn't point the link 2 your webpage